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CROCODILES

Crocodiles see well, their eyes are equipped with three eyelids, each having a different function. Their eyeballs slide back out of (1)__________ way during an attack. Should they lose one of their eight-centimetre-long teeth, a replacement is always ready. A crocodile may go through (2)__________ thousand teeth during a lifetime of over seventy years. Crocodiles can not chew, as their teeth are (3)_________ only to penetrate and hold. These animals can attack at any (4)_________ of the year, but they are more active in the warmer months and when in (5)__________ of mates. Underwater, crocodiles (6)___________ their victims at the water’s (7)__________ by sensing any movement in the water. Once they have a hold on their victim, they drag it deep into the water to (8)__________ it. They then crush and swallow it.

Many battles occur over mates. About six weeks after mating, the female (9)__________ a nest, often on the river bank, and (10)__________ about fifty eggs. She then seals the nest for protection and also as a way of (11)_________ the temperature. After ten to twelve weeks the baby crocodiles come out of the eggs: only about one percent of these (12)________ it to adulthood, as thousands die in flooding or are eaten by fish or bigger crocodiles. In an (13)__________ to ensure a source of (14)_________ animals, crocodile farms have been (15)__________ up, and a vast industry now exists in crocodile skin and meat.

1. A. harm’s B. danger’s C. injury’s D. damage’s

2. A. various B. several C. considerable D. numerous

3. A. composed B.constituted C. designed D. styled

4. A. time B. phase C. month D. interval

5. A. discovery B. hunt C. exploration D. search

6. A. prefer B. accept C. propose D. choose

7. A. border B. rim C. edge D. shore

8. A. sink B. drown C. capsize D. soak

9. A. installs B. makes C. manufactures D. produces

10. A. lays B. sets C. drops D. puts

11. A. dominating B. ruling C. imposing D. controlling

12. A. reach B. make C. get D. arrive

13. A. attempt B. action C. aspiration D. alternative

14. A. well B. fine C. fit D. healthy

15. A. put B. taken C. set D. stood

1
23 tháng 6 2017

tham khảo trang này bạn nhé

Đọc - Hiểu - Trang 6

Everyone knows that honeybees make honey, but how do they actually do it? Honeybees live in colonies, which means that they live with lots of other bees. Beehives, nests made of wax, are the places where they live and stow their honey. Honeybees drink nectar from flowers or other sweet deposits from plants or trees. The honey made by these bees is used to supply the colony with food during the cold winter when there arc no flowers to drink from. Thus, these bees not only consume the nectar for...
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Everyone knows that honeybees make honey, but how do they actually do it? Honeybees live in colonies, which means that they live with lots of other bees. Beehives, nests made of wax, are the places where they live and stow their honey.

Honeybees drink nectar from flowers or other sweet deposits from plants or trees. The honey made by these bees is used to supply the colony with food during the cold winter when there arc no flowers to drink from. Thus, these bees not only consume the nectar for nourishment but also bring it home. They have a special organ called a honey stomach which is used to carry the food to their colony.

When honeybees come back home, they regurgitate what they have put in their honey stomachs. Other honeybees in the hive come along and help them. They repeatedly eat and regurgitate many times until the product becomes somewhat digested. Next, the bees move the syrupy product into open honeycomb cells. Then they beat their wings to fan it to prevent fermentation. The fanning makes the water evaporate so that the product gets thick enough. Now it cannot easily be attacked by bacteria. Finally, it can be called honey. After this process, honeybees seal up the honeycomb cells with wax until they are hungry.

The most impressive part of this process is how seamlessly a bee colony works together. In a colony, there are female worker bees, male drones, and one queen bee. Although there are both male and females in the hive, the majority of the work is done by females. The female worker bees are in charge of taking care of the hive and creating honey. When they are young, they take care of feeding the young bee larvae. When they are older, they go out and bring nectar back to the hive, where they begin making honey. The male drones are responsible for fertilizing the eggs, but require little energy as they spend their time waiting around the hive. The single queen bee is responsible for the colony's survival. She is the only female that can lay eggs. The wonderful substance called honey would not exist without the bees' teamwork.

1. What is the main topic of the passage?

A. The role of the female honeybee
B. Preventing fermentation in honey
C. Why honeybees build huge wax nests
D. How a honeybee colony works to make honey

2. What can be inferred from the passage about honey? A. It's not always the same color
B. It is only liked by a minority of people
C. Watery honey can go bad easily
D. It is created and cared for by the queen bee 3. What do honeybees do to prevent fermentation? A. Blow air on the honey by waving their wings
B. Overproduce honey using their legs
C. Feed the larvae the unfermented honey
D. Bring the honey to the honeycomb cells 4. According to the passage, which of the following is NOT true of honeybees? A. They work together in their colony.
B. They produce honey through a complex process
C. The queen bee is responsible for making honey
D The worker bees work both inside and outside of their hive.
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Ex1:Gạch chân những từ trong ngoặc sao cho phù hợp với đoạn văn sau đây: (There/They/These) are different kinds of teeth:"incisors","molars" and"canies".(Any/Each/Some) kind has a diffent job.The incisors are the teeth(over/throught/at)the front of the mouth.We need them to cut our food. The molars are(the/a/an)biggest teeth in our mouths.Between the incisors and molars we have canies.They are longer(then/that/than)the other teeth. Children's first teeth...
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Ex1:Gạch chân những từ trong ngoặc sao cho phù hợp với đoạn văn sau đây:

(There/They/These) are different kinds of teeth:"incisors","molars" and"canies".(Any/Each/Some) kind has a diffent job.The incisors are the teeth(over/throught/at)the front of the mouth.We need them to cut our food.

The molars are(the/a/an)biggest teeth in our mouths.Between the incisors and molars we have canies.They are longer(then/that/than)the other teeth.

Children's first teeth are(calling/called/calls)"milk teeth".Children usually have twenty milk teeth and they have(all/every/ones)of them when they are about two years old.

When children are seven or eight years old they start to(get/got/getting) new teeth.Grown ups have thirty-two teeth.

It very important for us to look(for/after/into)our teeth.We should(cleaned/cleaning/clean)them with a toothbrush after every meal and it is good to go to dentist every six months

Ex2:Read the diary and write the missing words.Write one word on each line:

Tuesday31 July

On Sundaymorning we went ..........a walk near the river.Paul was...............us a story when we saw a sheep in the water.It couldn't swim.

Nick and I.............off our jackets and jumped into the river and we pulled the sheep ................of the water.

thw famer saw Nick and me with the sheep and he ran to help.then he said"Come back to my house,boys" and his wife gave..........some lemonade and snacks.

1
8 tháng 4 2017

Ex1:Gạch chân những từ trong ngoặc sao cho phù hợp với đoạn văn sau đây:

There are different kinds of teeth:"incisors","molars" and"canies".Each kind has a diffent job.The incisors are the teeth at the front of the mouth.We need them to cut our food.

The molars are the biggest teeth in our mouths.Between the incisors and molars we have canies.They are longer than the other teeth.

Children's first teeth are called "milk teeth".Children usually have twenty milk teeth and they have all of them when they are about two years old.

When children are seven or eight years old they start to get new teeth.Grown ups have thirty-two teeth.

It very important for us to look after our teeth.We should clean them with a toothbrush after every meal and it is good to go to dentist every six months

Ex2:Read the diary and write the missing words.Write one word on each line:

Tuesday31 July

On Sundaymorning we went ..for........a walk near the river.Paul was...telling............us a story when we saw a sheep in the water.It couldn't swim.

Nick and I....put.........off our jackets and jumped into the river and we pulled the sheep ....out............of the water.

thw famer saw Nick and me with the sheep and he ran to help.then he said"Come back to my house,boys" and his wife gave..us.......some lemonade and snacks.

Điền từ còn thiếu vào chỗ trống : Do you think the animals can understand each other ? The answer is yes . They can communicate (1) ........................ each other by signs and sounds . For example , dogs communicate in many ways . They not only bark , (2) .................... they howl , growl , snarl , and whine . They lift a paw , or bare their teeth . Other dogs can understand what these sounds and actions (3) ....................... Animals communicate with each other...
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Điền từ còn thiếu vào chỗ trống :

Do you think the animals can understand each other ?

The answer is yes . They can communicate (1) ........................ each other by signs and sounds . For example , dogs communicate in many ways . They not only bark , (2) .................... they howl , growl , snarl , and whine . They lift a paw , or bare their teeth . Other dogs can understand what these sounds and actions (3) .......................

Animals communicate with each other not only with sounds and movements , but with smell . Most animals that live in herds (4).......................on smell to keep together . And , of course , we know how dogs recognize each other by smell.

Apes are supposed (5) ...................among the most intelligent of animals , yet , they really have no better " language " than other animals . They make many sounds and expressions of the (6) .........................to communicate their feelings of anger or hunger or joy , but they have nothing like the words of human speech .

By the way , unlike human begings who have to learn (7) ........................talk , apes and other animals know their " language " by instinct . They will make the right kind of cries and sounds and expression even if they have never seen another animal like (8) ..............before . Birds , however , learn their way (9) .....................singing , at least in part . That is why a sparrow brought up among canaries will try (10) ......................like one . It has been learning the wrong " language "

1
5 tháng 4 2018

Do you think the animals can understand each other? The answer is yes. They can communicate to each other by signs and sounds. For example, dogs communicate in many ways. They not only bark, even they howl, growl, snarl, and whine. They lift a paw, or bare their teeth. Other dogs can understand what these sounds and actions mean_.
Animals communicate with each other not only with sounds and movements but with smell. Most animals that live in herds depend on smell to keep together. And, of course, we know how dogs recognize each other by smell.
Apes are supposed to be among the most intelligent of animals, yet, they really have no better “language” than other animals. They make many sounds and expressions of the mouth to communicate their feelings of anger or hunger or joy, but they have nothing like the words of human speech.
By the way, unlike human beings who have to learn how to talk, apes and other animals know their “language” by instinct. They will make the right kind of cries and sounds and expression even if they have never seen another animal like themselves before.
Birds, however, learn their way of singing, at least in part. That is why a sparrow brought up among canaries will try to sing like one. It has been learning the wrong “language”!

12 tháng 3 2017

Điển 1 từ vào ô trống:

Many thousands of chidren have accidents in their homes. As a (1)....result...., some died. The (2)...most... common accidents are with fire and hot water. Small chidren often touch pots of boiling water on the stove. The pots fall over and the hot water falls on the chidren and burns (3)..them... Some chidren like to play with (4)..fire... They enjoy striking mayches or throwing on a fire to (5)..mạke.. it burn brightly. If a fire gets to big, it gets out of (6).control.. Then the house catches fire. It is very dangerous to play with matches. When a child strikes a match, the flame soon burns near his fingers. Then he drops the match on the floor. Many houses(7)..catch... fire in this way.

Some kinds of clothing burns very easily. Many children have (8)..been... burned because they have stood too near a fire and their clothing has suddenly caught fire.

12 tháng 3 2017

Điển 1 từ vào ô trống:

Many thousands of chidren have accidents in their homes. As a (1)....result...., some died. The (2)...most... common accidents are with fire and hot water. Small chidren often touch pots of boiling water on the stove. The pots fall over and the hot water falls on the chidren and burns (3)..them... Some chidren like to play with (4)..fire... They enjoy striking mayches or throwing on a fire to (5)..mạke.. it burn brightly. If a fire gets to big, it gets out of (6).control.. Then the house catches fire. It is very dangerous to play with matches. When a child strikes a match, the flame soon burns near his fingers. Then he drops the match on the floor. Many houses(7)..catch... fire in this way.

Some kinds of clothing burns very easily. Many children have (8)..... burned because they have stood too near a fire and their clothing has suddenly caught fire.

Dịch đoạn văn sau: Many people from rural areas are leaving behind their traditional way of life and moving to the city. They believe that well-paying jobs are plentiful in the city. At home on the farm, life is always a straggle with nature. Typhoons, floods or droughts can easily destroy a harvest and leave the farmer with little or no money until the following year. Often fanners look for other work when they need more money for their family. The increase in population, however, has...
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Dịch đoạn văn sau:

Many people from rural areas are leaving behind their traditional way of life and moving to the city. They believe that well-paying jobs are plentiful in the city.

At home on the farm, life is always a straggle with nature. Typhoons, floods or droughts can easily destroy a harvest and leave the farmer with little or no money until the following year. Often fanners look for other work when they need more money for their family.

The increase in population, however, has led to overcrowding in many cities. This puts a strain on schools and hospitals, as well as water and electricity supplies. Increased pollution is another unpleasant result.

There is also a human side to this tragedy. Families sometimes have to live apart. In these cases, children may live at home with relatives, while their parents so and live in an urban area.

Governments all over the world are trying to provide facilities for these migrants, but it can be quite a problem.

2
11 tháng 12 2017

Nhiều người từ nông thôn đang bỏ lại cuộc sống truyền thống của họ và di chuyển đến thành phố. Họ tin rằng các công việc được trả lương cao đang dồi dào trong thành phố.

Tại nhà trong nông trại, cuộc sống luôn là sự lạc lõng với thiên nhiên. Bão, lũ lụt hoặc hạn hán có thể dễ dàng hủy hoại mùa màng và để lại cho nông dân ít hoặc không có tiền cho đến năm sau. Thường thì những người nông dân tìm kiếm những công việc khác khi họ cần nhiều tiền hơn cho gia đình họ.

Sự gia tăng dân số, tuy nhiên, đã dẫn đến sự quá tải ở nhiều thành phố. Điều này gây căng thẳng cho các trường học và bệnh viện, cũng như cung cấp nước và điện. Tình trạng ô nhiễm gia tăng là một kết quả khó chịu.

Cũng có một khía cạnh của con người đối với bi kịch này. Các gia đình đôi khi phải sống xa nhau. Trong những trường hợp này, trẻ em có thể sống ở nhà với người thân, trong khi cha mẹ chúng và sống ở khu vực thành thị.

Chính phủ các nước trên thế giới đang cố gắng cung cấp cơ sở cho những người di cư, nhưng có thể là một vấn đề.

11 tháng 12 2017

Google Dịch hả chế

ACCIDENTS IN THE HOME Many thousands of children have accidents in their homes. As a result some children die The most common (1)…………are with fire and hot water. Small children often touch pots of (2)……………water on the stove. The pots falls over and the water falls on the children and burns (3)…………... Some children like to play with fire. They enjoy striking matches or throwing things on a fire to make it burn brightly If the fire gets too big, it gets out of (4)…………...Then the house...
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ACCIDENTS IN THE HOME

Many thousands of children have accidents in their homes. As a result some children die

The most common (1)…………are with fire and hot water. Small children often touch pots of (2)……………water on the stove. The pots falls over and the water falls on the children and burns (3)…………... Some children like to play with fire. They enjoy striking matches or throwing things on a fire to make it burn brightly If the fire gets too big, it gets out of (4)…………...Then the house (5)…………..fire. It is very dangerous to play with matches. When a child strikes a match, the flame soon burns near his fingers. Then he (6)…………..the match on the floor. Many houses catch fire in this way

Although fire and hot water cause most accidents in the home, many children cut (7)…………..with knives. Others get an electric (8)………….Some children are made very ill from taking their parents’medicine. Many children have to go to hospital every year because they thought a box of medicine was a box of (9)………….

There is only one good way to see to it that accidents do not (10)…………..in the home : do not touch anything that is dangerous

1
31 tháng 3 2018

Many thousands of children have accidents in their homes. As a result some children died. The most common accident are with fire and hot water. Small children often touch pots of boiling water on the stove. The pots fall over and the hot water falls on the children and burns them. Some children like to play with fire. They enjoy striking matches or throwing things on a fire to make burn brightly. It is very dangerous to play with matches. When a child strikes a match, the flame soon burns near his fingers . The drops the match on the floor. Many houses catch fire in this way. Some kids of clothing burn very easily. Many children has been badly burned because they stood too near a fire and their clothing has suddenly caught fire. Although fire and hot water cause most accidents in their homes, many children cut themselves with knives . Other yet an electric shock. Some children are made very ill from taking their parents medicine. Many small children have to go to hospital every year because they thought a box of medicine was a box of sweets. There is only one good way to see to it that accidents do not happen in the home. Do not touch anything that is dangerous

ACCIDENTS IN THE HOME Many thousands of children have accidents in their homes. As a result some children die The most common (1)…………are with fire and hot water. Small children often touch pots of (2)……………water on the stove. The pots falls over and the water falls on the children and burns (3)…………... Some children like to play with fire. They enjoy striking matches or throwing things on a fire to make it burn brightly If the fire gets too big, it gets out of (4)…………...Then the house...
Đọc tiếp

ACCIDENTS IN THE HOME

Many thousands of children have accidents in their homes. As a result some children die

The most common (1)…………are with fire and hot water. Small children often touch pots of (2)……………water on the stove. The pots falls over and the water falls on the children and burns (3)…………... Some children like to play with fire. They enjoy striking matches or throwing things on a fire to make it burn brightly If the fire gets too big, it gets out of (4)…………...Then the house (5)…………..fire. It is very dangerous to play with matches. When a child strikes a match, the flame soon burns near his fingers. Then he (6)…………..the match on the floor. Many houses catch fire in this way

Although fire and hot water cause most accidents in the home, many children cut (7)…………..with knives. Others get an electric (8)………….Some children are made very ill from taking their parents’medicine. Many children have to go to hospital every year because they thought a box of medicine was a box of (9)………….

There is only one good way to see to it that accidents do not (10)…………..in the home : do not touch anything that is dangerous

2
7 tháng 4 2018

ACCIDENTS IN THE HOME

Many thousands of children have accidents in their homes. As a result some children die

The most common (1)…ACCIDENTS………are with fire and hot water. Small children often touch pots of (2)…BOILING…………water on the stove. The pots falls over and the water falls on the children and burns (3)…THEM………... Some children like to play with fire. They enjoy striking matches or throwing things on a fire to make it burn brightly If the fire gets too big, it gets out of (4)…CONTROL………...Then the house (5)…CATCHES………..fire. It is very dangerous to play with matches. When a child strikes a match, the flame soon burns near his fingers. Then he (6)…DROPS………..the match on the floor. Many houses catch fire in this way

Although fire and hot water cause most accidents in the home, many children cut (7)…THEMSELVES………..with knives. Others get an electric (8)…SHOCK……….Some children are made very ill from taking their parents’medicine. Many children have to go to hospital every year because they thought a box of medicine was a box of (9)…SWEETS……….

There is only one good way to see to it that accidents do not (10)…HAPPEN………..in the home : do not touch anything that is dangerous

8 tháng 4 2018

ACCIDENTS IN THE HOME

Many thousands of children have accidents in their homes. As a result some children die

The most common (1) ACCIDENTS are with fire and hot water. Small children often touch pots of (2) BOILING water on the stove. The pots falls over and the water falls on the children and burns (3) THEM. Some children like to play with fire. They enjoy striking matches or throwing things on a fire to make it burn brightly If the fire gets too big, it gets out of (4) CONTROL.Then the house (5) CATCHES fire. It is very dangerous to play with matches. When a child strikes a match, the flame soon burns near his fingers. Then he (6) DROPS the match on the floor. Many houses catch fire in this way.

Although fire and hot water cause most accidents in the home, many children cut (7)THEMSELVES with knives. Others get an electric (8) SHOCK. Some children are made very ill from taking their parents’medicine. Many children have to go to hospital every year because they thought a box of medicine was a box of (9) SWEETS.

There is only one good way to see to it that accidents do not (10) HAPPEN in the home : do not touch anything that is dangerous.

Mọi người giúp vs ạ! :(( Old Mr. Langly (1) ............alone in a big house with a beautiful garden, However, she always (2)____________ lonely as no one ever came to visit him. One day, a family of six (3) _____________ into the house next to Mr. Langly’s. He was very (4) ___________, so he went over to welcome them. He also told the children that they could play in his garden. His new neighbors were very glad and their children have continued to play in Mr. Langly’s garden ever...
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Mọi người giúp vs ạ! :((

Old Mr. Langly (1) ............alone in a big house with a beautiful garden, However, she always (2)____________ lonely as no one ever came to visit him. One day, a family of six (3) _____________ into the house next to Mr. Langly’s. He was very (4) ___________, so he went over to welcome them. He also told the children that they could play in his garden. His new neighbors were very glad and their children have continued to play in Mr. Langly’s garden ever since. Our next door neighbors are (5) _________ inconsiderate people. They always play loud music at odd hours of the day. They do not care if the people living on either side of their house are asleep or resting. They are (6) ___________ quarrelsome a lot. They always shout at each other at the top of their voices. Not (7)_____________ do they cause embarrassment but they cause a lot of inconvenience. Once, I came home from school (8) _____________ they were having a fight. As I had to pass their flat to get to mine, I had to walk along the corridor in front of their house. Unfortunately, a pot, which the wife threw at her husband, hit me on my head. I had a bump on my head for a few days after that.

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Read the following passage and choose the best answer for each of the questions. 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 pet dog or cat include lass of playfulness and energy, a decline in hearing and eyesight, or even a slight...
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Read the following passage and choose the best answer for each of the questions.

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 pet dog or cat include lass 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 age occurs in the arteries, the blood vessels that lead from the heart. They become thickened and constricted, allowing less blood to flow 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 may times during the course of a lifetime. Nerve cells and muscle fibers can never be replace 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.

1. What does the word “it” in line 2 refer to?

A. aging B. a living thing C. an illness D. an accident

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

A. the graying of the hair B. the wrinkling of the skin

C. the decline in hearing and eyesight. D. the loss of appetite

3. When does the human body begin to lose vigor and the ability to function efficiency?

A. Soon after reaching adulthood B. During childhood

C. Early adulthood D. Past middle age

4. What happens to memorization when the brain begins to age?

A. It works less B. It becomes forgetful

C. It declines D. It slows down

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

A. All living things grow old.

B. Aging is unavoidable in any livings things.

C. Plants show less signs of aging than any other living things.

D. Most body parts wear out during the courses of a lifetime.

1
3 tháng 2 2018

Read the following passage and choose the best answer for each of the questions.

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 pet dog or cat include lass 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 age occurs in the arteries, the blood vessels that lead from the heart. They become thickened and constricted, allowing less blood to flow 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 may times during the course of a lifetime. Nerve cells and muscle fibers can never be replace 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.

1. What does the word “it” in line 2 refer to?

A. aging B. a living thing C. an illness D. an accident

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

A. the graying of the hair B. the wrinkling of the skin

C. the decline in hearing and eyesight. D. the loss of appetite

3. When does the human body begin to lose vigor and the ability to function efficiency?

A. Soon after reaching adulthood B. During childhood

C. Early adulthood D. Past middle age

4. What happens to memorization when the brain begins to age?

A. It works less B. It becomes forgetful

C. It declines D. It slows down

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

A. All living things grow old.

B. Aging is unavoidable in any livings things.

C. Plants show less signs of aging than any other living things.

D. Most body parts wear out during the courses of a lifetime.