Some animal behaviorists argue that certain animals can remember past events, anticipate future ones, make plans and choices, and coordinate activities within a group. These scientists, however, are cautious about the extent to which animals can be credited with conscious   processing.
Explanations of animal behavior that leave out any sort of consciousness at all and ascribe actions entirely to instinct leave many questions unanswered. One example of such unexplained behavior: Honeybees communicate the sources of nectar to one another by doing a dance in a figure-eight pattern. The orientation of the dance conveys the position of the food relative to the sun's position in the sky, and the speed of the dance tells how  far  the food source is from  the  hive. Most researchers assume that the ability to perform and  encode the dance is innate and  shows no special intelligence. But in one study, when experimenters kept changing the site of     the food source, each time moving the food 25 percent father from the previous site, foraging honeybees began to anticipate where the food source would appear next. When the researchers arrived at the new location, they would find the bees circling the spot, waiting for their food. No one has yet explained how bees, whose brains weigh four ten-thousandths of an  ounce,  could  have inferred the location of the new  site.
Other behaviors that may indicate some cognition include tool use. Many animals, like the otter who uses a stone to crack mussel shells, are capable of using objects in the natural environment as rudimentary tools. One researcher has found that mother  chimpanzees  occasionally show their young how to use tools to open hard nuts. In one study, chimpanzees compared two pairs of food wells containing chocolate chips. One pair might contain, say, five chips and three chips, the other four chips and three chips. Allowed to choose which pair they wanted, the  chimpanzees  almost always chose the  one with the higher total, showing some sort  of summing ability. Other chimpanzees have learned to use numerals to label quantities of items and do simple sums.

What did researchers  discover in the study of honeybees discussed in paragraph 2?

Some animal behaviorists argue that certain animals can remember past events, anticipate future ones, make plans and choices, and coordinate activities within a group. These scientists, however, are cautious about the extent to which animals can be credited with conscious   processing.
Explanations of animal behavior that leave out any sort of consciousness at all and ascribe actions entirely to instinct leave many questions unanswered. One example of such unexplained behavior: Honeybees communicate the sources of nectar to one another by doing a dance in a figure-eight pattern. The orientation of the dance conveys the position of the food relative to the sun's position in the sky, and the speed of the dance tells how  far  the food source is from  the  hive. Most researchers assume that the ability to perform and  encode the dance is innate and  shows no special intelligence. But in one study, when experimenters kept changing the site of     the food source, each time moving the food 25 percent father from the previous site, foraging honeybees began to anticipate where the food source would appear next. When the researchers arrived at the new location, they would find the bees circling the spot, waiting for their food. No one has yet explained how bees, whose brains weigh four ten-thousandths of an  ounce,  could  have inferred the location of the new  site.
Other behaviors that may indicate some cognition include tool use. Many animals, like the otter who uses a stone to crack mussel shells, are capable of using objects in the natural environment as rudimentary tools. One researcher has found that mother  chimpanzees  occasionally show their young how to use tools to open hard nuts. In one study, chimpanzees compared two pairs of food wells containing chocolate chips. One pair might contain, say, five chips and three chips, the other four chips and three chips. Allowed to choose which pair they wanted, the  chimpanzees  almost always chose the  one with the higher total, showing some sort  of summing ability. Other chimpanzees have learned to use numerals to label quantities of items and do simple sums.

The word "yet" is closest in  meaning to  ...............

Some animal behaviorists argue that certain animals can remember past events, anticipate future ones, make plans and choices, and coordinate activities within a group. These scientists, however, are cautious about the extent to which animals can be credited with conscious   processing.
Explanations of animal behavior that leave out any sort of consciousness at all and ascribe actions entirely to instinct leave many questions unanswered. One example of such unexplained behavior: Honeybees communicate the sources of nectar to one another by doing a dance in a figure-eight pattern. The orientation of the dance conveys the position of the food relative to the sun's position in the sky, and the speed of the dance tells how  far  the food source is from  the  hive. Most researchers assume that the ability to perform and  encode the dance is innate and  shows no special intelligence. But in one study, when experimenters kept changing the site of     the food source, each time moving the food 25 percent father from the previous site, foraging honeybees began to anticipate where the food source would appear next. When the researchers arrived at the new location, they would find the bees circling the spot, waiting for their food. No one has yet explained how bees, whose brains weigh four ten-thousandths of an  ounce,  could  have inferred the location of the new  site.
Other behaviors that may indicate some cognition include tool use. Many animals, like the otter who uses a stone to crack mussel shells, are capable of using objects in the natural environment as rudimentary tools. One researcher has found that mother  chimpanzees  occasionally show their young how to use tools to open hard nuts. In one study, chimpanzees compared two pairs of food wells containing chocolate chips. One pair might contain, say, five chips and three chips, the other four chips and three chips. Allowed to choose which pair they wanted, the  chimpanzees  almost always chose the  one with the higher total, showing some sort  of summing ability. Other chimpanzees have learned to use numerals to label quantities of items and do simple sums.

What is the purpose of the honeybee at a site?

Some animal behaviorists argue that certain animals can remember past events, anticipate future ones, make plans and choices, and coordinate activities within a group. These scientists, however, are cautious about the extent to which animals can be credited with conscious   processing.
Explanations of animal behavior that leave out any sort of consciousness at all and ascribe actions entirely to instinct leave many questions unanswered. One example of such unexplained behavior: Honeybees communicate the sources of nectar to one another by doing a dance in a figure-eight pattern. The orientation of the dance conveys the position of the food relative to the sun's position in the sky, and the speed of the dance tells how  far  the food source is from  the  hive. Most researchers assume that the ability to perform and  encode the dance is innate and  shows no special intelligence. But in one study, when experimenters kept changing the site of     the food source, each time moving the food 25 percent father from the previous site, foraging honeybees began to anticipate where the food source would appear next. When the researchers arrived at the new location, they would find the bees circling the spot, waiting for their food. No one has yet explained how bees, whose brains weigh four ten-thousandths of an  ounce,  could  have inferred the location of the new  site.
Other behaviors that may indicate some cognition include tool use. Many animals, like the otter who uses a stone to crack mussel shells, are capable of using objects in the natural environment as rudimentary tools. One researcher has found that mother  chimpanzees  occasionally show their young how to use tools to open hard nuts. In one study, chimpanzees compared two pairs of food wells containing chocolate chips. One pair might contain, say, five chips and three chips, the other four chips and three chips. Allowed to choose which pair they wanted, the  chimpanzees  almost always chose the  one with the higher total, showing some sort  of summing ability. Other chimpanzees have learned to use numerals to label quantities of items and do simple sums.

Which of the following is NOT discussed as an ability animals are thought to have?

Some animal behaviorists argue that certain animals can remember past events, anticipate future ones, make plans and choices, and coordinate activities within a group. These scientists, however, are cautious about the extent to which animals can be credited with conscious   processing.

Explanations of animal behavior that leave out any sort of consciousness at all and ascribe actions entirely to instinct leave many questions unanswered. One example of such unexplained behavior: Honeybees communicate the sources of nectar to one another by doing a dance in a figure-eight pattern. The orientation of the dance conveys the position of the food relative to the sun's position in the sky, and the speed of the dance tells how  far  the food source is from  the  hive. Most researchers assume that the ability to perform and  encode the dance is innate and  shows no special intelligence. But in one study, when experimenters kept changing the site of     the food source, each time moving the food 25 percent father from the previous site, foraging honeybees began to anticipate where the food source would appear next. When the researchers arrived at the new location, they would find the bees circling the spot, waiting for their food. No one has yet explained how bees, whose brains weigh four ten-thousandths of an  ounce,  could  have inferred the location of the new  site.

Other behaviors that may indicate some cognition include tool use. Many animals, like the otter who uses a stone to crack mussel shells, are capable of using objects in the natural environment as rudimentary tools. One researcher has found that mother  chimpanzees  occasionally show their young how to use tools to open hard nuts. In one study, chimpanzees compared two pairs of food wells containing chocolate chips. One pair might contain, say, five chips and three chips, the other four chips and three chips. Allowed to choose which pair they wanted, the  chimpanzees  almost always chose the  one with the higher total, showing some sort  of summing ability. Other chimpanzees have learned to use numerals to label quantities of items and do simple sums.

What does the passage mainly  discuss?

Water scarcity is fast becoming one of the major limiting factors in world crop production.  In many areas, poor agricultural practices have led to increasing desertification and the loss of formerly arable lands. Consequently, those plants species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.
Plants uses several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilages which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria ant plant pets.
Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizers availability, attacked by pets, and poor storage after harvesting

All of the following are examples of an adverse situation for crops EXCEPT...............

Water scarcity is fast becoming one of the major limiting factors in world crop production.  In many areas, poor agricultural practices have led to increasing desertification and the loss of formerly arable lands. Consequently, those plants species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.
Plants uses several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilages which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria ant plant pets.
Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizers availability, attacked by pets, and poor storage after harvesting

It can be inferred that synthetic simulated waxes.......................

Water scarcity is fast becoming one of the major limiting factors in world crop production.  In many areas, poor agricultural practices have led to increasing desertification and the loss of formerly arable lands. Consequently, those plants species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.
Plants uses several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilages which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria ant plant pets.
Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizers availability, attacked by pets, and poor storage after harvesting

What is an example of an inorganic agent that may attack plants?

Water scarcity is fast becoming one of the major limiting factors in world crop production.  In many areas, poor agricultural practices have led to increasing desertification and the loss of formerly arable lands. Consequently, those plants species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.
Plants uses several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilages which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria ant plant pets.
Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizers availability, attacked by pets, and poor storage after harvesting

The word "aggression" is closest in meaning to...................

Water scarcity is fast becoming one of the major limiting factors in world crop production.  In many areas, poor agricultural practices have led to increasing desertification and the loss of formerly arable lands. Consequently, those plants species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.
Plants uses several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilages which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria ant plant pets.
Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizers availability, attacked by pets, and poor storage after harvesting

The word "it" refers to......................

Water scarcity is fast becoming one of the major limiting factors in world crop production.  In many areas, poor agricultural practices have led to increasing desertification and the loss of formerly arable lands. Consequently, those plants species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.
Plants uses several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilages which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria ant plant pets.
Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizers availability, attacked by pets, and poor storage after harvesting

Which is one of the ways in which the epicuticular wax protects the plant?

Water scarcity is fast becoming one of the major limiting factors in world crop production.  In many areas, poor agricultural practices have led to increasing desertification and the loss of formerly arable lands. Consequently, those plants species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.
Plants uses several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilages which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria ant plant pets.
Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizers availability, attacked by pets, and poor storage after harvesting

The word "extensive" is closest in meaning to.........................

Water scarcity is fast becoming one of the major limiting factors in world crop production.  In many areas, poor agricultural practices have led to increasing desertification and the loss of formerly arable lands. Consequently, those plants species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.
Plants uses several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilages which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria ant plant pets.
Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizers availability, attacked by pets, and poor storage after harvesting

The word "extensive" is closest in meaning to.........................

Water scarcity is fast becoming one of the major limiting factors in world crop production.  In many areas, poor agricultural practices have led to increasing desertification and the loss of formerly arable lands. Consequently, those plants species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.
Plants uses several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilages which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria ant plant pets.
Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizers availability, attacked by pets, and poor storage after harvesting

Which of the following is a mechanical or physical mechanism that desert plants use?

Water scarcity is fast becoming one of the major limiting factors in world crop production.  In many areas, poor agricultural practices have led to increasing desertification and the loss of formerly arable lands. Consequently, those plants species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.
Plants uses several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilages which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria ant plant pets.
Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizers availability, attacked by pets, and poor storage after harvesting

The word "arable" is closest in meaning to..................

Water scarcity is fast becoming one of the major limiting factors in world crop production.  In many areas, poor agricultural practices have led to increasing desertification and the loss of formerly arable lands. Consequently, those plants species that are well adapted to survival in dry climates are being looked at for an answer in developing more efficient crops to grow on marginally arable lands.

Plants uses several mechanisms to ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to chemical mechanisms. Many plants, such as cacti, have internal gums and mucilages which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to protect the plant. It prevents excessive loss of internal moisture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria ant plant pets.

Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to greatly increase a plant's ability to maintain health in such adverse situations as inadequate water supply, limited fertilizers availability, attacked by pets, and poor storage after harvesting

This passage deals mainly with.......................

PANDEMIC DISEASES
Diseases are a natural part of life on earth. If there were  no diseases,  the population would grow too quickly, and there would not be enough food or other resources, so in a way, diseases are natural ways of keeping the Earth in balance. But sometimes  they  spread  very  quickly and kill large numbers of people. For example, in 1918, an outbreak of the flu spread  across the world, killing over 25 million people in only six months. Such terrible outbreaks of a disease are called pandemics.
Pandemics happen when a disease changes in a way that our bodies are not prepared to fight.  In 1918, a new type of flu virus appeared. Our bodies had no way to fight this new flu virus, and    so it spread very quickly and killed large numbers of people. While there have  been  many  different pandemic diseases throughout history, all of them have a new thing in    common.
First, all pandemic diseases spread from one person to another very   easily.
Second, while they may kill many people, they generally do not kill people very quickly. A good example of this would be the Marburg virus. The Marburg virus is an extremely infectious disease. In addition, it is deadly. About 70 -80% of all people who  get the Marburg virus  died  from the disease. However, the Marburg virus has not become  a pandemic  because most people die within three days of getting the disease. This means that the virus does not have enough time    to spread a large number of people. The flu virus of 1918, on the other hand, generally took about   a week to ten days to kill its victims, so it had more time to   spread.
While we may never be able to completely stop pandemics, we  can  make  them  less  common. Doctors carefully monitor new diseases that they fear could become pandemics. For example, in 2002, and 2003, doctors carefully watched SARS. Their health warnings may have prevented SARS from becoming a  pandemic.

This passage is mainly about   ................

PANDEMIC DISEASES
Diseases are a natural part of life on earth. If there were  no diseases,  the population would grow too quickly, and there would not be enough food or other resources, so in a way, diseases are natural ways of keeping the Earth in balance. But sometimes  they  spread  very  quickly and kill large numbers of people. For example, in 1918, an outbreak of the flu spread  across the world, killing over 25 million people in only six months. Such terrible outbreaks of a disease are called pandemics.
Pandemics happen when a disease changes in a way that our bodies are not prepared to fight.  In 1918, a new type of flu virus appeared. Our bodies had no way to fight this new flu virus, and    so it spread very quickly and killed large numbers of people. While there have  been  many  different pandemic diseases throughout history, all of them have a new thing in    common.
First, all pandemic diseases spread from one person to another very   easily.
Second, while they may kill many people, they generally do not kill people very quickly. A good example of this would be the Marburg virus. The Marburg virus is an extremely infectious disease. In addition, it is deadly. About 70 -80% of all people who  get the Marburg virus  died  from the disease. However, the Marburg virus has not become  a pandemic  because most people die within three days of getting the disease. This means that the virus does not have enough time    to spread a large number of people. The flu virus of 1918, on the other hand, generally took about   a week to ten days to kill its victims, so it had more time to   spread.
While we may never be able to completely stop pandemics, we  can  make  them  less  common. Doctors carefully monitor new diseases that they fear could become pandemics. For example, in 2002, and 2003, doctors carefully watched SARS. Their health warnings may have prevented SARS from becoming a  pandemic.

The author mentions SARS in order  to    ....................

PANDEMIC DISEASES
Diseases are a natural part of life on earth. If there were  no diseases,  the population would grow too quickly, and there would not be enough food or other resources, so in a way, diseases are natural ways of keeping the Earth in balance. But sometimes  they  spread  very  quickly and kill large numbers of people. For example, in 1918, an outbreak of the flu spread  across the world, killing over 25 million people in only six months. Such terrible outbreaks of a disease are called pandemics.
Pandemics happen when a disease changes in a way that our bodies are not prepared to fight.  In 1918, a new type of flu virus appeared. Our bodies had no way to fight this new flu virus, and    so it spread very quickly and killed large numbers of people. While there have  been  many  different pandemic diseases throughout history, all of them have a new thing in    common.
First, all pandemic diseases spread from one person to another very   easily.
Second, while they may kill many people, they generally do not kill people very quickly. A good example of this would be the Marburg virus. The Marburg virus is an extremely infectious disease. In addition, it is deadly. About 70 -80% of all people who  get the Marburg virus  died  from the disease. However, the Marburg virus has not become  a pandemic  because most people die within three days of getting the disease. This means that the virus does not have enough time    to spread a large number of people. The flu virus of 1918, on the other hand, generally took about   a week to ten days to kill its victims, so it had more time to   spread.
While we may never be able to completely stop pandemics, we  can  make  them  less  common. Doctors carefully monitor new diseases that they fear could become pandemics. For example, in 2002, and 2003, doctors carefully watched SARS. Their health warnings may have prevented SARS from becoming a  pandemic.

The word 'monitor' in the passage is closest in  meaning to  ................

PANDEMIC DISEASES
Diseases are a natural part of life on earth. If there were  no diseases,  the population would grow too quickly, and there would not be enough food or other resources, so in a way, diseases are natural ways of keeping the Earth in balance. But sometimes  they  spread  very  quickly and kill large numbers of people. For example, in 1918, an outbreak of the flu spread  across the world, killing over 25 million people in only six months. Such terrible outbreaks of a disease are called pandemics.
Pandemics happen when a disease changes in a way that our bodies are not prepared to fight.  In 1918, a new type of flu virus appeared. Our bodies had no way to fight this new flu virus, and    so it spread very quickly and killed large numbers of people. While there have  been  many  different pandemic diseases throughout history, all of them have a new thing in    common.
First, all pandemic diseases spread from one person to another very   easily.
Second, while they may kill many people, they generally do not kill people very quickly. A good example of this would be the Marburg virus. The Marburg virus is an extremely infectious disease. In addition, it is deadly. About 70 -80% of all people who  get the Marburg virus  died  from the disease. However, the Marburg virus has not become  a pandemic  because most people die within three days of getting the disease. This means that the virus does not have enough time to spread a large number of people. The flu virus of 1918, on the other hand, generally took about   a week to ten days to kill its victims, so it had more time to spread.
While we may never be able to completely stop pandemics, we  can  make  them  less  common. Doctors carefully monitor new diseases that they fear could become pandemics. For example, in 2002, and 2003, doctors carefully watched SARS. Their health warnings may have prevented SARS from becoming a  pandemic.

According to paragraph 3, why hasn't Marburg virus become a pandemic?

PANDEMIC DISEASES
Diseases are a natural part of life on earth. If there were  no diseases,  the population would grow too quickly, and there would not be enough food or other resources, so in a way, diseases are natural ways of keeping the Earth in balance. But sometimes  they  spread  very  quickly and kill large numbers of people. For example, in 1918, an outbreak of the flu spread  across the world, killing over 25 million people in only six months. Such terrible outbreaks of a disease are called pandemics.
Pandemics happen when a disease changes in a way that our bodies are not prepared to fight.  In 1918, a new type of flu virus appeared. Our bodies had no way to fight this new flu virus, and    so it spread very quickly and killed large numbers of people. While there have  been  many  different pandemic diseases throughout history, all of them have a new thing in    common.
First, all pandemic diseases spread from one person to another very   easily.
Second, while they may kill many people, they generally do not kill people very quickly. A good example of this would be the Marburg virus. The Marburg virus is an extremely infectious disease. In addition, it is deadly. About 70 -80% of all people who  get the Marburg virus  died  from the disease. However, the Marburg virus has not become  a pandemic  because most people die within three days of getting the disease. This means that the virus does not have enough time    to spread a large number of people. The flu virus of 1918, on the other hand, generally took about   a week to ten days to kill its victims, so it had more time to   spread.
While we may never be able to completely stop pandemics, we  can  make  them  less  common. Doctors carefully monitor new diseases that they fear could become pandemics. For example, in 2002, and 2003, doctors carefully watched SARS. Their health warnings may have prevented SARS from becoming a  pandemic.

Which of the following is mentioned as a common feature of all pandemic diseases?

PANDEMIC DISEASES
Diseases are a natural part of life on earth. If there were  no diseases,  the population would grow too quickly, and there would not be enough food or other resources, so in a way, diseases are natural ways of keeping the Earth in balance. But sometimes  they  spread  very  quickly and kill large numbers of people. For example, in 1918, an outbreak of the flu spread  across the world, killing over 25 million people in only six months. Such terrible outbreaks of a disease are called pandemics.
Pandemics happen when a disease changes in a way that our bodies are not prepared to fight.  In 1918, a new type of flu virus appeared. Our bodies had no way to fight this new flu virus, and so it spread very quickly and killed large numbers of people. While there have  been  many  different pandemic diseases throughout history, all of them have a new thing in common.
First, all pandemic diseases spread from one person to another very easily.
Second, while they may kill many people, they generally do not kill people very quickly. A good example of this would be the Marburg virus. The Marburg virus is an extremely infectious disease. In addition, it is deadly. About 70 -80% of all people who  get the Marburg virus  died  from the disease. However, the Marburg virus has not become  a pandemic  because most people die within three days of getting the disease. This means that the virus does not have enough time    to spread a large number of people. The flu virus of 1918, on the other hand, generally took about   a week to ten days to kill its victims, so it had more time to   spread.
While we may never be able to completely stop pandemics, we  can  make  them  less  common. Doctors carefully monitor new diseases that they fear could become pandemics. For example, in 2002, and 2003, doctors carefully watched SARS. Their health warnings may have prevented SARS from becoming a  pandemic.

The word "it" in the passage  refers to ......................

PANDEMIC DISEASES
Diseases are a natural part of life on earth. If there were  no diseases,  the population would grow too quickly, and there would not be enough food or other resources, so in a way, diseases are natural ways of keeping the Earth in balance. But sometimes  they  spread  very  quickly and kill large numbers of people. For example, in 1918, an outbreak of the flu spread  across the world, killing over 25 million people in only six months. Such terrible outbreaks of a disease are called pandemics.
Pandemics happen when a disease changes in a way that our bodies are not prepared to fight.  In 1918, a new type of flu virus appeared. Our bodies had no way to fight this new flu virus, and    so it spread very quickly and killed large numbers of people. While there have  been  many  different pandemic diseases throughout history, all of them have a new thing in    common.
First, all pandemic diseases spread from one person to another very   easily.
Second, while they may kill many people, they generally do not kill people very quickly. A good example of this would be the Marburg virus. The Marburg virus is an extremely infectious disease. In addition, it is deadly. About 70 -80% of all people who  get the Marburg virus  died  from the disease. However, the Marburg virus has not become  a pandemic  because most people die within three days of getting the disease. This means that the virus does not have enough time    to spread a large number of people. The flu virus of 1918, on the other hand, generally took about   a week to ten days to kill its victims, so it had more time to   spread.
While we may never be able to completely stop pandemics, we  can  make  them  less  common. Doctors carefully monitor new diseases that they fear could become pandemics. For example, in 2002, and 2003, doctors carefully watched SARS. Their health warnings may have prevented SARS from becoming a  pandemic.

According to the passage, all of the following are true of the 1918 flu pandemic EXCEPT that    ..............

PANDEMIC DISEASES
Diseases are a natural part of life on earth. If there were  no diseases,  the population would grow too quickly, and there would not be enough food or other resources, so in a way, diseases are natural ways of keeping the Earth in balance. But sometimes  they  spread  very  quickly and kill large numbers of people. For example, in 1918, an outbreak of the flu spread  across the world, killing over 25 million people in only six months. Such terrible outbreaks of a disease are called pandemics.
Pandemics happen when a disease changes in a way that our bodies are not prepared to fight.  In 1918, a new type of flu virus appeared. Our bodies had no way to fight this new flu virus, and    so it spread very quickly and killed large numbers of people. While there have  been  many  different pandemic diseases throughout history, all of them have a new thing in    common.
First, all pandemic diseases spread from one person to another very   easily.
Second, while they may kill many people, they generally do not kill people very quickly. A good example of this would be the Marburg virus. The Marburg virus is an extremely infectious disease. In addition, it is deadly. About 70 -80% of all people who  get the Marburg virus  died  from the disease. However, the Marburg virus has not become  a pandemic  because most people die within three days of getting the disease. This means that the virus does not have enough time    to spread a large number of people. The flu virus of 1918, on the other hand, generally took about   a week to ten days to kill its victims, so it had more time to   spread.
While we may never be able to completely stop pandemics, we  can  make  them  less  common. Doctors carefully monitor new diseases that they fear could become pandemics. For example, in 2002, and 2003, doctors carefully watched SARS. Their health warnings may have prevented SARS from becoming a  pandemic.

According to the passage, what causes pandemics?

PANDEMIC DISEASES
Diseases are a natural part of life on earth. If there were  no diseases,  the population would grow too quickly, and there would not be enough food or other resources, so in a way, diseases are natural ways of keeping the Earth in balance. But sometimes  they  spread  very  quickly and kill large numbers of people. For example, in 1918, an outbreak of the flu spread  across the world, killing over 25 million people in only six months. Such terrible outbreaks of a disease are called pandemics.
Pandemics happen when a disease changes in a way that our bodies are not prepared to fight.  In 1918, a new type of flu virus appeared. Our bodies had no way to fight this new flu virus, and    so it spread very quickly and killed large numbers of people. While there have  been  many  different pandemic diseases throughout history, all of them have a new thing in    common.
First, all pandemic diseases spread from one person to another very   easily.
Second, while they may kill many people, they generally do not kill people very quickly. A good example of this would be the Marburg virus. The Marburg virus is an extremely infectious disease. In addition, it is deadly. About 70 -80% of all people who  get the Marburg virus  died  from the disease. However, the Marburg virus has not become  a pandemic  because most people die within three days of getting the disease. This means that the virus does not have enough time    to spread a large number of people. The flu virus of 1918, on the other hand, generally took about   a week to ten days to kill its victims, so it had more time to   spread.
While we may never be able to completely stop pandemics, we  can  make  them  less  common. Doctors carefully monitor new diseases that they fear could become pandemics. For example, in 2002, and 2003, doctors carefully watched SARS. Their health warnings may have prevented SARS from becoming a  pandemic.

Based on the information in the passage the term "pandemics'' can be explained as.....................

PANDEMIC DISEASES

Diseases are a natural part of life on earth. If there were  no diseases,  the population would grow too quickly, and there would not be enough food or other resources, so in a way, diseases are natural ways of keeping the Earth in balance. But sometimes  they  spread  very  quickly and kill large numbers of people. For example, in 1918, an outbreak of the flu spread  across the world, killing over 25 million people in only six months. Such terrible outbreaks of a disease are called pandemics.

Pandemics happen when a disease changes in a way that our bodies are not prepared to fight.  In 1918, a new type of flu virus appeared. Our bodies had no way to fight this new flu virus, and    so it spread very quickly and killed large numbers of people. While there have  been  many  different pandemic diseases throughout history, all of them have a new thing in    common.

First, all pandemic diseases spread from one person to another very   easily.

Second, while they may kill many people, they generally do not kill people very quickly. A good example of this would be the Marburg virus. The Marburg virus is an extremely infectious disease. In addition, it is deadly. About 70 -80% of all people who  get the Marburg virus  died  from the disease. However, the Marburg virus has not become  a pandemic  because most people die within three days of getting the disease. This means that the virus does not have enough time    to spread a large number of people. The flu virus of 1918, on the other hand, generally took about   a week to ten days to kill its victims, so it had more time to   spread.

While we may never be able to completely stop pandemics, we  can  make  them  less  common. Doctors carefully monitor new diseases that they fear could become pandemics. For example, in 2002, and 2003, doctors carefully watched SARS. Their health warnings may have prevented SARS from becoming a  pandemic.

 According to paragraph 1, how are diseases a natural part of life on   Earth?

Aging is the process of growing old. It occurs eventually in every living thing provided, of course, that an illness or accident does not kill it prematurely. The most familiar outward signs of aging may be seen in old people, such as the graying of the hair and the wrinkling of the skin. Signs of aging in a pot dog or cat include loss of playfulness and energy, a decline in hearing and eyesight, or even a slight graying of the coat. Plants age too, but the signs are much harder to detect.
Most body parts grow bigger and stronger, and function more efficiently during childhood. They reach their peak at the time of maturity, or early adulthood. After that, they begin to decline. Bones, for example, gradually become lighter and more brittle. In the aged, the joints between the bones also become rigid and more inflexible. This can make moving very painful.
All the major organs of the body show signs of aging. The brain, for example, works less efficiently, and even gets smaller in size. Thinking processes of all sorts are slowed  down. Old people often have trouble in remembering recent events.
One of the most serious changes of old ago occurs in the arteries, the blood vessels that lead from the heart. They become thickened and constricted, allowing less blood to flow to  the rest of body. This condition accounts, directly or indirectly, for many of the diseases of the aged. It may, for example, result In heart attack.
Aging is not a uniform process. Different parts of the body wear out at different rates. There are great differences among people in their rate of aging. Even the cells of the body differ in the way they age. The majority of cells are capable of reproducing themselves many times during the course of a lifetime. Nerve cells and muscle fibers can never be replaced  once they wear out.
Gerontologists - scientists who study the process of aging - believe this wearing out of the body is controlled by a built-in biological time-clock. They are trying to discover how this clock works so that they can slow down the process. This could give man a longer life and a great number of productive years.

What is the main idea of the last paragraph?

Aging is the process of growing old. It occurs eventually in every living thing provided, of course, that an illness or accident does not kill it prematurely. The most familiar outward signs of aging may be seen in old people, such as the graying of the hair and the wrinkling of the skin. Signs of aging in a pot dog or cat include loss of playfulness and energy, a decline in hearing and eyesight, or even a slight graying of the coat. Plants age too, but the signs are much harder to detect.
Most body parts grow bigger and stronger, and function more efficiently during childhood. They reach their peak at the time of maturity, or early adulthood. After that, they begin to decline. Bones, for example, gradually become lighter and more brittle. In the aged, the joints between the bones also become rigid and more inflexible. This can make moving very painful.
All the major organs of the body show signs of aging. The brain, for example, works less efficiently, and even gets smaller in size. Thinking processes of all sorts are slowed  down. Old people often have trouble in remembering recent events.
One of the most serious changes of old ago occurs in the arteries, the blood vessels that lead from the heart. They become thickened and constricted, allowing less blood to flow to  the rest of body. This condition accounts, directly or indirectly, for many of the diseases of the aged. It may, for example, result In heart attack.
Aging is not a uniform process. Different parts of the body wear out at different rates. There are great differences among people in their rate of aging. Even the cells of the body differ in the way they age. The majority of cells are capable of reproducing themselves many times during the course of a lifetime. Nerve cells and muscle fibers can never be replaced  once they wear out.
Gerontologists - scientists who study the process of aging - believe this wearing out of the body is controlled by a built-in biological time-clock. They are trying to discover how this clock works so that they can slow down the process. This could give man a longer life and a great number of productive years.

According to the passage, which of the following is NOT true?

Aging is the process of growing old. It occurs eventually in every living thing provided, of course, that an illness or accident does not kill it prematurely. The most familiar outward signs of aging may be seen in old people, such as the graying of the hair and the wrinkling of the skin. Signs of aging in a pot dog or cat include loss of playfulness and energy, a decline in hearing and eyesight, or even a slight graying of the coat. Plants age too, but the signs are much harder to detect.
Most body parts grow bigger and stronger, and function more efficiently during childhood. They reach their peak at the time of maturity, or early adulthood. After that, they begin to decline. Bones, for example, gradually become lighter and more brittle. In the aged, the joints between the bones also become rigid and more inflexible. This can make moving very painful.
All the major organs of the body show signs of aging. The brain, for example, works less efficiently, and even gets smaller in size. Thinking processes of all sorts are slowed  down. Old people often have trouble in remembering recent events.
One of the most serious changes of old ago occurs in the arteries, the blood vessels that lead from the heart. They become thickened and constricted, allowing less blood to flow to  the rest of body. This condition accounts, directly or indirectly, for many of the diseases of the aged. It may, for example, result In heart attack.
Aging is not a uniform process. Different parts of the body wear out at different rates. There are great differences among people in their rate of aging. Even the cells of the body differ in the way they age. The majority of cells are capable of reproducing themselves many times during the course of a lifetime. Nerve cells and muscle fibers can never be replaced  once they wear out.
Gerontologists - scientists who study the process of aging - believe this wearing out of the body is controlled by a built-in biological time-clock. They are trying to discover how this clock works so that they can slow down the process. This could give man a longer life and a great number of productive years.

According to the passage, what condition is responsible for many of the diseases of the old?

Aging is the process of growing old. It occurs eventually in every living thing provided, of course, that an illness or accident does not kill it prematurely. The most familiar outward signs of aging may be seen in old people, such as the graying of the hair and the wrinkling of the skin. Signs of aging in a pot dog or cat include loss of playfulness and energy, a decline in hearing and eyesight, or even a slight graying of the coat. Plants age too, but the signs are much harder to detect.
Most body parts grow bigger and stronger, and function more efficiently during childhood. They reach their peak at the time of maturity, or early adulthood. After that, they begin to decline. Bones, for example, gradually become lighter and more brittle. In the aged, the joints between the bones also become rigid and more inflexible. This can make moving very painful.
All the major organs of the body show signs of aging. The brain, for example, works less efficiently, and even gets smaller in size. Thinking processes of all sorts are slowed  down. Old people often have trouble in remembering recent events.
One of the most serious changes of old ago occurs in the arteries, the blood vessels that lead from the heart. They become thickened and constricted, allowing less blood to flow to  the rest of body. This condition accounts, directly or indirectly, for many of the diseases of the aged. It may, for example, result In heart attack.
Aging is not a uniform process. Different parts of the body wear out at different rates. There are great differences among people in their rate of aging. Even the cells of the body differ in the way they age. The majority of cells are capable of reproducing themselves many times during the course of a lifetime. Nerve cells and muscle fibers can never be replaced  once they wear out.
Gerontologists - scientists who study the process of aging - believe this wearing out of the body is controlled by a built-in biological time-clock. They are trying to discover how this clock works so that they can slow down the process. This could give man a longer life and a great number of productive years.

The word "brittle" as used in the second paragraph means ......................

Aging is the process of growing old. It occurs eventually in every living thing provided, of course, that an illness or accident does not kill it prematurely. The most familiar outward signs of aging may be seen in old people, such as the graying of the hair and the wrinkling of the skin. Signs of aging in a pot dog or cat include loss of playfulness and energy, a decline in hearing and eyesight, or even a slight graying of the coat. Plants age too, but the signs are much harder to detect.
Most body parts grow bigger and stronger, and function more efficiently during childhood. They reach their peak at the time of maturity, or early adulthood. After that, they begin to decline. Bones, for example, gradually become lighter and more brittle. In the aged, the joints between the bones also become rigid and more inflexible. This can make moving very painful.
All the major organs of the body show signs of aging. The brain, for example, works less efficiently, and even gets smaller in size. Thinking processes of all sorts are slowed  down. Old people often have trouble in remembering recent events.
One of the most serious changes of old ago occurs in the arteries, the blood vessels that lead from the heart. They become thickened and constricted, allowing less blood to flow to  the rest of body. This condition accounts, directly or indirectly, for many of the diseases of the aged. It may, for example, result In heart attack.
Aging is not a uniform process. Different parts of the body wear out at different rates. There are great differences among people in their rate of aging. Even the cells of the body differ in the way they age. The majority of cells are capable of reproducing themselves many times during the course of a lifetime. Nerve cells and muscle fibers can never be replaced  once they wear out.
Gerontologists - scientists who study the process of aging - believe this wearing out of the body is controlled by a built-in biological time-clock. They are trying to discover how this clock works so that they can slow down the process. This could give man a longer life and a great number of productive years.

What does "Aging is not a uniform process" mean?

Aging is the process of growing old. It occurs eventually in every living thing provided, of course, that an illness or accident does not kill it prematurely. The most familiar outward signs of aging may be seen in old people, such as the graying of the hair and the wrinkling of the skin. Signs of aging in a pot dog or cat include loss of playfulness and energy, a decline in hearing and eyesight, or even a slight graying of the coat. Plants age too, but the signs are much harder to detect.
Most body parts grow bigger and stronger, and function more efficiently during childhood. They reach their peak at the time of maturity, or early adulthood. After that, they begin to decline. Bones, for example, gradually become lighter and more brittle. In the aged, the joints between the bones also become rigid and more inflexible. This can make moving very painful.
All the major organs of the body show signs of aging. The brain, for example, works less efficiently, and even gets smaller in size. Thinking processes of all sorts are slowed  down. Old people often have trouble in remembering recent events.
One of the most serious changes of old ago occurs in the arteries, the blood vessels that lead from the heart. They become thickened and constricted, allowing less blood to flow to  the rest of body. This condition accounts, directly or indirectly, for many of the diseases of the aged. It may, for example, result In heart attack.
Aging is not a uniform process. Different parts of the body wear out at different rates. There are great differences among people in their rate of aging. Even the cells of the body differ in the way they age. The majority of cells are capable of reproducing themselves many times during the course of a lifetime. Nerve cells and muscle fibers can never be replaced  once they wear out.
Gerontologists - scientists who study the process of aging - believe this wearing out of the body is controlled by a built-in biological time-clock. They are trying to discover how this clock works so that they can slow down the process. This could give man a longer life and a great number of productive years.

What happens to memorization when the brain begins to age?

Aging is the process of growing old. It occurs eventually in every living thing provided, of course, that an illness or accident does not kill it prematurely. The most familiar outward signs of aging may be seen in old people, such as the graying of the hair and the wrinkling of the skin. Signs of aging in a pot dog or cat include loss of playfulness and energy, a decline in hearing and eyesight, or even a slight graying of the coat. Plants age too, but the signs are much harder to detect.
Most body parts grow bigger and stronger, and function more efficiently during childhood. They reach their peak at the time of maturity, or early adulthood. After that, they begin to decline. Bones, for example, gradually become lighter and more brittle. In the aged, the joints between the bones also become rigid and more inflexible. This can make moving very painful.
All the major organs of the body show signs of aging. The brain, for example, works less efficiently, and even gets smaller in size. Thinking processes of all sorts are slowed  down. Old people often have trouble in remembering recent events.
One of the most serious changes of old ago occurs in the arteries, the blood vessels that lead from the heart. They become thickened and constricted, allowing less blood to flow to  the rest of body. This condition accounts, directly or indirectly, for many of the diseases of the aged. It may, for example, result In heart attack.
Aging is not a uniform process. Different parts of the body wear out at different rates. There are great differences among people in their rate of aging. Even the cells of the body differ in the way they age. The majority of cells are capable of reproducing themselves many times during the course of a lifetime. Nerve cells and muscle fibers can never be replaced  once they wear out.
Gerontologists - scientists who study the process of aging - believe this wearing out of the body is controlled by a built-in biological time-clock. They are trying to discover how this clock works so that they can slow down the process. This could give man a longer life and a great number of productive years.

When does the human body begin to lose vigor and the ability to function efficiently?

Aging is the process of growing old. It occurs eventually in every living thing provided, of course, that an illness or accident does not kill it prematurely. The most familiar outward signs of aging may be seen in old people, such as the graying of the hair and the wrinkling of the skin. Signs of aging in a pot dog or cat include loss of playfulness and energy, a decline in hearing and eyesight, or even a slight graying of the coat. Plants age too, but the signs are much harder to detect.
Most body parts grow bigger and stronger, and function more efficiently during childhood. They reach their peak at the time of maturity, or early adulthood. After that, they begin to decline. Bones, for example, gradually become lighter and more brittle. In the aged, the joints between the bones also become rigid and more inflexible. This can make moving very painful.
All the major organs of the body show signs of aging. The brain, for example, works less efficiently, and even gets smaller in size. Thinking processes of all sorts are slowed  down. Old people often have trouble in remembering recent events.
One of the most serious changes of old ago occurs in the arteries, the blood vessels that lead from the heart. They become thickened and constricted, allowing less blood to flow to  the rest of body. This condition accounts, directly or indirectly, for many of the diseases of the aged. It may, for example, result In heart attack.
Aging is not a uniform process. Different parts of the body wear out at different rates. There are great differences among people in their rate of aging. Even the cells of the body differ in the way they age. The majority of cells are capable of reproducing themselves many times during the course of a lifetime. Nerve cells and muscle fibers can never be replaced  once they wear out.
Gerontologists - scientists who study the process of aging - believe this wearing out of the body is controlled by a built-in biological time-clock. They are trying to discover how this clock works so that they can slow down the process. This could give man a longer life and a great number of productive years.

All of the followings may be the outward signs of aging EXCEPT      ................

Aging is the process of growing old. It occurs eventually in every living thing provided, of course, that an illness or accident does not kill it prematurely. The most familiar outward signs of aging may be seen in old people, such as the graying of the hair and the wrinkling of the skin. Signs of aging in a pot dog or cat include loss of playfulness and energy, a decline in hearing and eyesight, or even a slight graying of the coat. Plants age too, but the signs are much harder to detect.
Most body parts grow bigger and stronger, and function more efficiently during childhood. They reach their peak at the time of maturity, or early adulthood. After that, they begin to decline. Bones, for example, gradually become lighter and more brittle. In the aged, the joints between the bones also become rigid and more inflexible. This can make moving very painful.
All the major organs of the body show signs of aging. The brain, for example, works less efficiently, and even gets smaller in size. Thinking processes of all sorts are slowed  down. Old people often have trouble in remembering recent events.
One of the most serious changes of old ago occurs in the arteries, the blood vessels that lead from the heart. They become thickened and constricted, allowing less blood to flow to  the rest of body. This condition accounts, directly or indirectly, for many of the diseases of the aged. It may, for example, result In heart attack.
Aging is not a uniform process. Different parts of the body wear out at different rates. There are great differences among people in their rate of aging. Even the cells of the body differ in the way they age. The majority of cells are capable of reproducing themselves many times during the course of a lifetime. Nerve cells and muscle fibers can never be replaced  once they wear out.
Gerontologists - scientists who study the process of aging - believe this wearing out of the body is controlled by a built-in biological time-clock. They are trying to discover how this clock works so that they can slow down the process. This could give man a longer life and a great number of productive years.

What is the main idea of the first paragraph?

Aging is the process of growing old. It occurs eventually in every living thing provided, of course, that an illness or accident does not kill it prematurely. The most familiar outward signs of aging may be seen in old people, such as the graying of the hair and the wrinkling of the skin. Signs of aging in a pot dog or cat include loss of playfulness and energy, a decline in hearing and eyesight, or even a slight graying of the coat. Plants age too, but the signs are much harder to detect.

Most body parts grow bigger and stronger, and function more efficiently during childhood. They reach their peak at the time of maturity, or early adulthood. After that, they begin to decline. Bones, for example, gradually become lighter and more brittle. In the aged, the joints between the bones also become rigid and more inflexible. This can make moving very painful.

All the major organs of the body show signs of aging. The brain, for example, works less efficiently, and even gets smaller in size. Thinking processes of all sorts are slowed  down. Old people often have trouble in remembering recent events.

One of the most serious changes of old ago occurs in the arteries, the blood vessels that lead from the heart. They become thickened and constricted, allowing less blood to flow to  the rest of body. This condition accounts, directly or indirectly, for many of the diseases of the aged. It may, for example, result In heart attack.

Aging is not a uniform process. Different parts of the body wear out at different rates. There are great differences among people in their rate of aging. Even the cells of the body differ in the way they age. The majority of cells are capable of reproducing themselves many times during the course of a lifetime. Nerve cells and muscle fibers can never be replaced  once they wear out.

Gerontologists - scientists who study the process of aging - believe this wearing out of the body is controlled by a built-in biological time-clock. They are trying to discover how this clock works so that they can slow down the process. This could give man a longer life and a great number of productive years

What does the word "it" in line 2 refers to?

Birds that feed in flocks commonly retire together into roosts. The reasons for roosting communally are not always obvious, but there are some likely benefits, In winter especially, it is important for birds to keep warm at night and conserve precious food reserves. One way to do this is to find a sheltered roost. Solitary roosters shelter in dense vegetation or enter a cavity- horned, larks dig holes In the ground and ptarmigan burrow into snow banks- but the effect of sheltering is magnified by several birds huddling together in the roost, as wrens, swifts, brown creepers, bluebirds, and anis do. Body contact reduces the surface area exposed to the cold air, so the birds keep each other warm. Two kinglets huddling together were found to reduce their heat losses by a quarter and three together saved a third of their heat.

The second possible benefit of communal roosts is that they act as "information centers". During the day, parties of birds will have spread out to forage over a very large area. When they return in the evening some will have fed well, but others may have found little to eat. Some investigators have observed that when the birds set out again next morning, those birds that did not feed well on the previous day appear to follow those that did. The behavior of common and lesser kestrels may illustrate different feeding behaviors of similar birds with different roosting habits. The common kestrel hunts vertebrate animals in a small, familiar hunting ground, whereas the very similar lesser kestrel feeds on insects over a large area. The common kestrel roost and hunts alone, but the lesser kestrel roosts and hunts in flocks, possibly so one bird can learn from others where to find insect swarms. Finally, there is safety in numbers at communal roosts since there will always be a few birds awake at any given moment to give the alarm. But this increased protection is partially counteracted by the fact that mass roosts attract predators and are especially vulnerable if they are on the ground. Even those in trees can be attacked by birds of prey. The birds on the edge are at greatest risk since predators find it easier to catch small birds perching at the margins of the roost

Which of the following is a disadvantage of communal roosts that is mentioned in the passage?

Birds that feed in flocks commonly retire together into roosts. The reasons for roosting communally are not always obvious, but there are some likely benefits, In winter especially, it is important for birds to keep warm at night and conserve precious food reserves. One way to do this is to find a sheltered roost. Solitary roosters shelter in dense vegetation or enter a cavity- horned, larks dig holes In the ground and ptarmigan burrow into snow banks- but the effect of sheltering is magnified by several birds huddling together in the roost, as wrens, swifts, brown creepers, bluebirds, and anis do. Body contact reduces the surface area exposed to the cold air, so the birds keep each other warm. Two kinglets huddling together were found to reduce their heat losses by a quarter and three together saved a third of their heat.

The second possible benefit of communal roosts is that they act as "information centers". During the day, parties of birds will have spread out to forage over a very large area. When they return in the evening some will have fed well, but others may have found little to eat. Some investigators have observed that when the birds set out again next morning, those birds that did not feed well on the previous day appear to follow those that did. The behavior of common and lesser kestrels may illustrate different feeding behaviors of similar birds with different roosting habits. The common kestrel hunts vertebrate animals in a small, familiar hunting ground, whereas the very similar lesser kestrel feeds on insects over a large area. The common kestrel roost and hunts alone, but the lesser kestrel roosts and hunts in flocks, possibly so one bird can learn from others where to find insect swarms. Finally, there is safety in numbers at communal roosts since there will always be a few birds awake at any given moment to give the alarm. But this increased protection is partially counteracted by the fact that mass roosts attract predators and are especially vulnerable if they are on the ground. Even those in trees can be attacked by birds of prey. The birds on the edge are at greatest risk since predators find it easier to catch small birds perching at the margins of the roost

Which of the following is not mentioned in the passage as an advantage derived by birds that huddle together while sleeping?

Birds that feed in flocks commonly retire together into roosts. The reasons for roosting communally are not always obvious, but there are some likely benefits, In winter especially, it is important for birds to keep warm at night and conserve precious food reserves. One way to do this is to find a sheltered roost. Solitary roosters shelter in dense vegetation or enter a cavity- horned, larks dig holes In the ground and ptarmigan burrow into snow banks- but the effect of sheltering is magnified by several birds huddling together in the roost, as wrens, swifts, brown creepers, bluebirds, and anis do. Body contact reduces the surface area exposed to the cold air, so the birds keep each other warm. Two kinglets huddling together were found to reduce their heat losses by a quarter and three together saved a third of their heat.

The second possible benefit of communal roosts is that they act as "information centers". During the day, parties of birds will have spread out to forage over a very large area. When they return in the evening some will have fed well, but others may have found little to eat. Some investigators have observed that when the birds set out again next morning, those birds that did not feed well on the previous day appear to follow those that did. The behavior of common and lesser kestrels may illustrate different feeding behaviors of similar birds with different roosting habits. The common kestrel hunts vertebrate animals in a small, familiar hunting ground, whereas the very similar lesser kestrel feeds on insects over a large area. The common kestrel roost and hunts alone, but the lesser kestrel roosts and hunts in flocks, possibly so one bird can learn from others where to find insect swarms. Finally, there is safety in numbers at communal roosts since there will always be a few birds awake at any given moment to give the alarm. But this increased protection is partially counteracted by the fact that mass roosts attract predators and are especially vulnerable if they are on the ground. Even those in trees can be attacked by birds of prey. The birds on the edge are at greatest risk since predators find it easier to catch small birds perching at the margins of the roost

The word "counteracted" is closest in meaning to...................

Birds that feed in flocks commonly retire together into roosts. The reasons for roosting communally are not always obvious, but there are some likely benefits, In winter especially, it is important for birds to keep warm at night and conserve precious food reserves. One way to do this is to find a sheltered roost. Solitary roosters shelter in dense vegetation or enter a cavity- horned, larks dig holes In the ground and ptarmigan burrow into snow banks- but the effect of sheltering is magnified by several birds huddling together in the roost, as wrens, swifts, brown creepers, bluebirds, and anis do. Body contact reduces the surface area exposed to the cold air, so the birds keep each other warm. Two kinglets huddling together were found to reduce their heat losses by a quarter and three together saved a third of their heat.

The second possible benefit of communal roosts is that they act as "information centers". During the day, parties of birds will have spread out to forage over a very large area. When they return in the evening some will have fed well, but others may have found little to eat. Some investigators have observed that when the birds set out again next morning, those birds that did not feed well on the previous day appear to follow those that did. The behavior of common and lesser kestrels may illustrate different feeding behaviors of similar birds with different roosting habits. The common kestrel hunts vertebrate animals in a small, familiar hunting ground, whereas the very similar lesser kestrel feeds on insects over a large area. The common kestrel roost and hunts alone, but the lesser kestrel roosts and hunts in flocks, possibly so one bird can learn from others where to find insect swarms. Finally, there is safety in numbers at communal roosts since there will always be a few birds awake at any given moment to give the alarm. But this increased protection is partially counteracted by the fact that mass roosts attract predators and are especially vulnerable if they are on the ground. Even those in trees can be attacked by birds of prey. The birds on the edge are at greatest risk since predators find it easier to catch small birds perching at the margins of the roost

Which of the following statements about lesser and common kestrels is true?

Birds that feed in flocks commonly retire together into roosts. The reasons for roosting communally are not always obvious, but there are some likely benefits, In winter especially, it is important for birds to keep warm at night and conserve precious food reserves. One way to do this is to find a sheltered roost. Solitary roosters shelter in dense vegetation or enter a cavity- horned, larks dig holes In the ground and ptarmigan burrow into snow banks- but the effect of sheltering is magnified by several birds huddling together in the roost, as wrens, swifts, brown creepers, bluebirds, and anis do. Body contact reduces the surface area exposed to the cold air, so the birds keep each other warm. Two kinglets huddling together were found to reduce their heat losses by a quarter and three together saved a third of their heat.

The second possible benefit of communal roosts is that they act as "information centers". During the day, parties of birds will have spread out to forage over a very large area. When they return in the evening some will have fed well, but others may have found little to eat. Some investigators have observed that when the birds set out again next morning, those birds that did not feed well on the previous day appear to follow those that did. The behavior of common and lesser kestrels may illustrate different feeding behaviors of similar birds with different roosting habits. The common kestrel hunts vertebrate animals in a small, familiar hunting ground, whereas the very similar lesser kestrel feeds on insects over a large area. The common kestrel roost and hunts alone, but the lesser kestrel roosts and hunts in flocks, possibly so one bird can learn from others where to find insect swarms. Finally, there is safety in numbers at communal roosts since there will always be a few birds awake at any given moment to give the alarm. But this increased protection is partially counteracted by the fact that mass roosts attract predators and are especially vulnerable if they are on the ground. Even those in trees can be attacked by birds of prey. The birds on the edge are at greatest risk since predators find it easier to catch small birds perching at the margins of the roost

The word "forage" is closest in meaning to....................

Birds that feed in flocks commonly retire together into roosts. The reasons for roosting communally are not always obvious, but there are some likely benefits, In winter especially, it is important for birds to keep warm at night and conserve precious food reserves. One way to do this is to find a sheltered roost. Solitary roosters shelter in dense vegetation or enter a cavity- horned, larks dig holes In the ground and ptarmigan burrow into snow banks- but the effect of sheltering is magnified by several birds huddling together in the roost, as wrens, swifts, brown creepers, bluebirds, and anis do. Body contact reduces the surface area exposed to the cold air, so the birds keep each other warm. Two kinglets huddling together were found to reduce their heat losses by a quarter and three together saved a third of their heat.

The second possible benefit of communal roosts is that they act as "information centers". During the day, parties of birds will have spread out to forage over a very large area. When they return in the evening some will have fed well, but others may have found little to eat. Some investigators have observed that when the birds set out again next morning, those birds that did not feed well on the previous day appear to follow those that did. The behavior of common and lesser kestrels may illustrate different feeding behaviors of similar birds with different roosting habits. The common kestrel hunts vertebrate animals in a small, familiar hunting ground, whereas the very similar lesser kestrel feeds on insects over a large area. The common kestrel roost and hunts alone, but the lesser kestrel roosts and hunts in flocks, possibly so one bird can learn from others where to find insect swarms. Finally, there is safety in numbers at communal roosts since there will always be a few birds awake at any given moment to give the alarm. But this increased protection is partially counteracted by the fact that mass roosts attract predators and are especially vulnerable if they are on the ground. Even those in trees can be attacked by birds of prey. The birds on the edge are at greatest risk since predators find it easier to catch small birds perching at the margins of the roost

The author mentions kinglets in line 8 as an example of birds that.....................

Birds that feed in flocks commonly retire together into roosts. The reasons for roosting communally are not always obvious, but there are some likely benefits, In winter especially, it is important for birds to keep warm at night and conserve precious food reserves. One way to do this is to find a sheltered roost. Solitary roosters shelter in dense vegetation or enter a cavity- horned, larks dig holes In the ground and ptarmigan burrow into snow banks- but the effect of sheltering is magnified by several birds huddling together in the roost, as wrens, swifts, brown creepers, bluebirds, and anis do. Body contact reduces the surface area exposed to the cold air, so the birds keep each other warm. Two kinglets huddling together were found to reduce their heat losses by a quarter and three together saved a third of their heat.

The second possible benefit of communal roosts is that they act as "information centers". During the day, parties of birds will have spread out to forage over a very large area. When they return in the evening some will have fed well, but others may have found little to eat. Some investigators have observed that when the birds set out again next morning, those birds that did not feed well on the previous day appear to follow those that did. The behavior of common and lesser kestrels may illustrate different feeding behaviors of similar birds with different roosting habits. The common kestrel hunts vertebrate animals in a small, familiar hunting ground, whereas the very similar lesser kestrel feeds on insects over a large area. The common kestrel roost and hunts alone, but the lesser kestrel roosts and hunts in flocks, possibly so one bird can learn from others where to find insect swarms. Finally, there is safety in numbers at communal roosts since there will always be a few birds awake at any given moment to give the alarm. But this increased protection is partially counteracted by the fact that mass roosts attract predators and are especially vulnerable if they are on the ground. Even those in trees can be attacked by birds of prey. The birds on the edge are at greatest risk since predators find it easier to catch small birds perching at the margins of the roost

The word "magnified" is closest in meaning to...................

Birds that feed in flocks commonly retire together into roosts. The reasons for roosting communally are not always obvious, but there are some likely benefits, In winter especially, it is important for birds to keep warm at night and conserve precious food reserves. One way to do this is to find a sheltered roost. Solitary roosters shelter in dense vegetation or enter a cavity- horned, larks dig holes In the ground and ptarmigan burrow into snow banks- but the effect of sheltering is magnified by several birds huddling together in the roost, as wrens, swifts, brown creepers, bluebirds, and anis do. Body contact reduces the surface area exposed to the cold air, so the birds keep each other warm. Two kinglets huddling together were found to reduce their heat losses by a quarter and three together saved a third of their heat.

The second possible benefit of communal roosts is that they act as "information centers". During the day, parties of birds will have spread out to forage over a very large area. When they return in the evening some will have fed well, but others may have found little to eat. Some investigators have observed that when the birds set out again next morning, those birds that did not feed well on the previous day appear to follow those that did. The behavior of common and lesser kestrels may illustrate different feeding behaviors of similar birds with different roosting habits. The common kestrel hunts vertebrate animals in a small, familiar hunting ground, whereas the very similar lesser kestrel feeds on insects over a large area. The common kestrel roost and hunts alone, but the lesser kestrel roosts and hunts in flocks, possibly so one bird can learn from others where to find insect swarms. Finally, there is safety in numbers at communal roosts since there will always be a few birds awake at any given moment to give the alarm. But this increased protection is partially counteracted by the fact that mass roosts attract predators and are especially vulnerable if they are on the ground. Even those in trees can be attacked by birds of prey. The birds on the edge are at greatest risk since predators find it easier to catch small birds perching at the margins of the roost

Ptarmigan keep warm in the winter by:

Birds that feed in flocks commonly retire together into roosts. The reasons for roosting communally are not always obvious, but there are some likely benefits, In winter especially, it is important for birds to keep warm at night and conserve precious food reserves. One way to do this is to find a sheltered roost. Solitary roosters shelter in dense vegetation or enter a cavity- horned, larks dig holes In the ground and ptarmigan burrow into snow banks- but the effect of sheltering is magnified by several birds huddling together in the roost, as wrens, swifts, brown creepers, bluebirds, and anis do. Body contact reduces the surface area exposed to the cold air, so the birds keep each other warm. Two kinglets huddling together were found to reduce their heat losses by a quarter and three together saved a third of their heat.

The second possible benefit of communal roosts is that they act as "information centers". During the day, parties of birds will have spread out to forage over a very large area. When they return in the evening some will have fed well, but others may have found little to eat. Some investigators have observed that when the birds set out again next morning, those birds that did not feed well on the previous day appear to follow those that did. The behavior of common and lesser kestrels may illustrate different feeding behaviors of similar birds with different roosting habits. The common kestrel hunts vertebrate animals in a small, familiar hunting ground, whereas the very similar lesser kestrel feeds on insects over a large area. The common kestrel roost and hunts alone, but the lesser kestrel roosts and hunts in flocks, possibly so one bird can learn from others where to find insect swarms. Finally, there is safety in numbers at communal roosts since there will always be a few birds awake at any given moment to give the alarm. But this increased protection is partially counteracted by the fact that mass roosts attract predators and are especially vulnerable if they are on the ground. Even those in trees can be attacked by birds of prey. The birds on the edge are at greatest risk since predators find it easier to catch small birds perching at the margins of the roost

The word "conserve" is closest in meaning to.................

Birds that feed in flocks commonly retire together into roosts. The reasons for roosting communally are not always obvious, but there are some likely benefits, In winter especially, it is important for birds to keep warm at night and conserve precious food reserves. One way to do this is to find a sheltered roost. Solitary roosters shelter in dense vegetation or enter a cavity- horned, larks dig holes In the ground and ptarmigan burrow into snow banks- but the effect of sheltering is magnified by several birds huddling together in the roost, as wrens, swifts, brown creepers, bluebirds, and anis do. Body contact reduces the surface area exposed to the cold air, so the birds keep each other warm. Two kinglets huddling together were found to reduce their heat losses by a quarter and three together saved a third of their heat.

The second possible benefit of communal roosts is that they act as "information centers". During the day, parties of birds will have spread out to forage over a very large area. When they return in the evening some will have fed well, but others may have found little to eat. Some investigators have observed that when the birds set out again next morning, those birds that did not feed well on the previous day appear to follow those that did. The behavior of common and lesser kestrels may illustrate different feeding behaviors of similar birds with different roosting habits. The common kestrel hunts vertebrate animals in a small, familiar hunting ground, whereas the very similar lesser kestrel feeds on insects over a large area. The common kestrel roost and hunts alone, but the lesser kestrel roosts and hunts in flocks, possibly so one bird can learn from others where to find insect swarms. Finally, there is safety in numbers at communal roosts since there will always be a few birds awake at any given moment to give the alarm. But this increased protection is partially counteracted by the fact that mass roosts attract predators and are especially vulnerable if they are on the ground. Even those in trees can be attacked by birds of prey. The birds on the edge are at greatest risk since predators find it easier to catch small birds perching at the margins of the roost

What does the passage mainly discuss?

Ranked as the number one beverage consumed worldwide, tea takes the lead over coffee in both popularity and production with more than 5 million metric tons of tea produced annually. Although much of this tea is consumed in Asia, European and African countries, the United  States drinks it fair share. According to estimates by the Tea Council of the United States, tea is enjoyed by no less than half of the U.S population on any given day. Black tea or green tea - iced, spiced, or instant - tea drinking has spurred a billion - dollar business with major tea produces in Africa and South America and throughout Asia.
Tea is made from the leaves of an evergreen plant, Camellia sinensis, which grows tall and lush in tropical regions. On tea plantation, the plant is kept trimmed to approximately four feet high, and as new buds called flush appear, they are plucked off by hand. Even in today's world of modern agricultural machinery, hand harvesting continues to be preferred method. Ideally, only the top two leaves and bud should be picked. This new growth produces the highest quality tea.
After being harvested, tea leaves are laid out on long drying racks, called withering racks, for 18 to 20 hours. During this process, the tea softens and becomes limp. Next, depending on the type of the tea being produced, the leaves may be crushed or chopped to release flavor, and then steamed to retain their green color, and the fermentation process is skipped. Producing black teas requires fermentation during which the tea leaves begin to darken. After fermentation, black tea is dried in vats to produce its rich brown or black color.
No one knows when or how tea became popular, but legend has it that tea as a beverage was discovered in 2737 B.C. by Emperor Shen Nung of China when leaves from Camellia dropped into his drinking water as it was boiling over a fire. As the story goes, Emperor Shen Nung drank the resulting liquid and proclaimed that the drink to be most nourishing and refreshing. Though this account cannot be documented, it is thought that tea drinking probably originated in China and spread to other parts of Asia, then to Europe, and ultimately to America colonies around 1650.
With about half of the caffeine content as coffee, tea is often chosen by those who want to reduce, but not necessarily eliminate their caffeine intake. Some people find that tea is less acidic than coffee and therefore easier on the stomach. Others have become interested in tea drinking since the National Cancer Institute published its findings on the antioxidant properties of tea. But whether tea is enjoyed for its perceived health benefits, its flavor, or as a social drink, teacups continue to be filled daily with the world's most popular beverage.

What best describes the topic of the passage?

Ranked as the number one beverage consumed worldwide, tea takes the lead over coffee in both popularity and production with more than 5 million metric tons of tea produced annually. Although much of this tea is consumed in Asia, European and African countries, the United  States drinks it fair share. According to estimates by the Tea Council of the United States, tea is enjoyed by no less than half of the U.S population on any given day. Black tea or green tea - iced, spiced, or instant - tea drinking has spurred a billion - dollar business with major tea produces in Africa and South America and throughout Asia.
Tea is made from the leaves of an evergreen plant, Camellia sinensis, which grows tall and lush in tropical regions. On tea plantation, the plant is kept trimmed to approximately four feet high, and as new buds called flush appear, they are plucked off by hand. Even in today's world of modern agricultural machinery, hand harvesting continues to be preferred method. Ideally, only the top two leaves and bud should be picked. This new growth produces the highest quality tea.
After being harvested, tea leaves are laid out on long drying racks, called withering racks, for 18 to 20 hours. During this process, the tea softens and becomes limp. Next, depending on the type of the tea being produced, the leaves may be crushed or chopped to release flavor, and then steamed to retain their green color, and the fermentation process is skipped. Producing black teas requires fermentation during which the tea leaves begin to darken. After fermentation, black tea is dried in vats to produce its rich brown or black color.
No one knows when or how tea became popular, but legend has it that tea as a beverage was discovered in 2737 B.C. by Emperor Shen Nung of China when leaves from Camellia dropped into his drinking water as it was boiling over a fire. As the story goes, Emperor Shen Nung drank the resulting liquid and proclaimed that the drink to be most nourishing and refreshing. Though this account cannot be documented, it is thought that tea drinking probably originated in China and spread to other parts of Asia, then to Europe, and ultimately to America colonies around 1650.
With about half of the caffeine content as coffee, tea is often chosen by those who want to reduce, but not necessarily eliminate their caffeine intake. Some people find that tea is less acidic than coffee and therefore easier on the stomach. Others have become interested in tea drinking since the National Cancer Institute published its findings on the antioxidant properties of tea. But whether tea is enjoyed for its perceived health benefits, its flavor, or as a social drink, teacups continue to be filled daily with the world's most popular beverage.

Where in the passage does the author mention research conducted on the beneficial effects of tea drinking?

Ranked as the number one beverage consumed worldwide, tea takes the lead over coffee in both popularity and production with more than 5 million metric tons of tea produced annually. Although much of this tea is consumed in Asia, European and African countries, the United  States drinks it fair share. According to estimates by the Tea Council of the United States, tea is enjoyed by no less than half of the U.S population on any given day. Black tea or green tea - iced, spiced, or instant - tea drinking has spurred a billion - dollar business with major tea produces in Africa and South America and throughout Asia.
Tea is made from the leaves of an evergreen plant, Camellia sinensis, which grows tall and lush in tropical regions. On tea plantation, the plant is kept trimmed to approximately four feet high, and as new buds called flush appear, they are plucked off by hand. Even in today's world of modern agricultural machinery, hand harvesting continues to be preferred method. Ideally, only the top two leaves and bud should be picked. This new growth produces the highest quality tea.
After being harvested, tea leaves are laid out on long drying racks, called withering racks, for 18 to 20 hours. During this process, the tea softens and becomes limp. Next, depending on the type of the tea being produced, the leaves may be crushed or chopped to release flavor, and then steamed to retain their green color, and the fermentation process is skipped. Producing black teas requires fermentation during which the tea leaves begin to darken. After fermentation, black tea is dried in vats to produce its rich brown or black color.
No one knows when or how tea became popular, but legend has it that tea as a beverage was discovered in 2737 B.C. by Emperor Shen Nung of China when leaves from Camellia dropped into his drinking water as it was boiling over a fire. As the story goes, Emperor Shen Nung drank the resulting liquid and proclaimed that the drink to be most nourishing and refreshing. Though this account cannot be documented, it is thought that tea drinking probably originated in China and spread to other parts of Asia, then to Europe, and ultimately to America colonies around 1650.
With about half of the caffeine content as coffee, tea is often chosen by those who want to reduce, but not necessarily eliminate their caffeine intake. Some people find that tea is less acidic than coffee and therefore easier on the stomach. Others have become interested in tea drinking since the National Cancer Institute published its findings on the antioxidant properties of tea. But whether tea is enjoyed for its perceived health benefits, its flavor, or as a social drink, teacups continue to be filled daily with the world's most popular beverage.

According to the passage, which may be the reason why someone would choose to drink tea instead of coffee?

Ranked as the number one beverage consumed worldwide, tea takes the lead over coffee in both popularity and production with more than 5 million metric tons of tea produced annually. Although much of this tea is consumed in Asia, European and African countries, the United  States drinks it fair share. According to estimates by the Tea Council of the United States, tea is enjoyed by no less than half of the U.S population on any given day. Black tea or green tea - iced, spiced, or instant - tea drinking has spurred a billion - dollar business with major tea produces in Africa and South America and throughout Asia.
Tea is made from the leaves of an evergreen plant, Camellia sinensis, which grows tall and lush in tropical regions. On tea plantation, the plant is kept trimmed to approximately four feet high, and as new buds called flush appear, they are plucked off by hand. Even in today's world of modern agricultural machinery, hand harvesting continues to be preferred method. Ideally, only the top two leaves and bud should be picked. This new growth produces the highest quality tea.
After being harvested, tea leaves are laid out on long drying racks, called withering racks, for 18 to 20 hours. During this process, the tea softens and becomes limp. Next, depending on the type of the tea being produced, the leaves may be crushed or chopped to release flavor, and then steamed to retain their green color, and the fermentation process is skipped. Producing black teas requires fermentation during which the tea leaves begin to darken. After fermentation, black tea is dried in vats to produce its rich brown or black color.
No one knows when or how tea became popular, but legend has it that tea as a beverage was discovered in 2737 B.C. by Emperor Shen Nung of China when leaves from Camellia dropped into his drinking water as it was boiling over a fire. As the story goes, Emperor Shen Nung drank the resulting liquid and proclaimed that the drink to be most nourishing and refreshing. Though this account cannot be documented, it is thought that tea drinking probably originated in China and spread to other parts of Asia, then to Europe, and ultimately to America colonies around 1650.
With about half of the caffeine content as coffee, tea is often chosen by those who want to reduce, but not necessarily eliminate their caffeine intake. Some people find that tea is less acidic than coffee and therefore easier on the stomach. Others have become interested in tea drinking since the National Cancer Institute published its findings on the antioxidant properties of tea. But whether tea is enjoyed for its perceived health benefits, its flavor, or as a social drink, teacups continue to be filled daily with the world's most popular beverage.

The word "eliminate" in paragraph 5 could be best replaced by?