Chemicals in our body the food into useful substances. [ ] A. break down B. break off C. break in D. break out 题目和参考答案——青夏教育精英家教网—

题目内容

Chemicals in our body _________ the food into useful substances.

[ ]

A. break down B. break off C. break in D. break out

答案：A

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There is an old saying in English： "Laughter is the best medicine". Until recently, few people took the saying very seriously. Now, however, doctors have begun to investigate laughter and the effects it has on the human body. They have found evidence that laughter really can improve people's health.

Tests were carried out to study the effects of laughter on the body. People watched funny films, while doctors checked their heart rate, blood pressure, breathing and muscles. It was found that laughter has similar effects to physical exercise. It increases blood pressure, the heart rate and the rate of breathing； it also works several groups of muscles in the face, the stomach, and even the feet. If laughter exercises the body, it must be beneficial.

Other tests have shown that laughter appears to be capable of reducing the effect of pain on the body. In one experiment doctors produced pain in groups of students who listened to different radio programs. The group which tolerated the pain for the longest time was 'the group which listened to a funny program. The reason why laughter can reduce pain seems to be that it helps to produce endorphins （内啡肽） in the brain. These are natural chemicals which diminish both stress and pain.

There is also some evidence to suggest that laughter helps the body's immune(免疫的)system, that is, the system which fights infection. In an experiment, one group of students watched a funny video while another group served as the control group - in other words, a group with which to compare the first group. Doctors checked the blood of the students in both groups and found that the people in the group that watched the video had an increase in the activity of their white blood cells, that is, the cells which fight infection.

As a result of these discoveries, some doctors and psychiatrists （精神病学家） in the United States now hold laughter clinics, in which they try to improve their patients' condition by encouraging them to laugh. They have found that even if their patients do not really feel like laughing, making them smile is enough to produce beneficial effects similar to those caused by laughter.

We learn from the first paragraph that laughter____________________.

A. is good for one's health

B. is related to some illness

C. has been investigated long since

D. has no effect on the body

Doctors have found that laughter_______________________.

A. keeps down blood pressure.

B. has similar effects to physical exercise

C. decreases the heart rate

D. increases stress

Which of the following statements is NOT true of laughter, according to the passage?

A. It reduces pain.

B. It exercises the body.

C. It improves the body's immune system.

D. It can cure cancer.

The writer's attitude towards laughter is__________.

A. critical

B. doubtful

C. positive

D. negative

NOT all memories are sweet. Some people spend all their lives trying to forget bad experiences. Violence and traffic accidents can leave people with terrible physical and emotional scars. Often they relive these experiences in nightmares.

Now American researchers think they are close to developing a pill, which will help people forget bad memories. The pill is designed to be taken immediately after a frightening experience. They hope it might reduce, or possibly wipe out, the effect of painful memories.

In November, experts tested a drug on people in the US and France. The drug stops the body releasing chemicals that fix memories in the brain. So far the research has suggested that only the emotional effects of memories may be reduced, not that the memories are wiped out. They are not sure to what degree people’s memories are affected.

The research has caused a great deal of argument. Some think it is a bad idea, while others support it.

Supporters say it could lead to pills that prevent or treat soldiers' troubling memories after war.

They say that there are many people who suffer from terrible memories.

"Some memories can ruin people's lives. They come back to you when you don't want to have them in a daydream or nightmare. They usually come with very painful emotions," said Roger Pitman, a professor of psychiatry at Harvard Medical School. "This could relieve a lot of that suffering."

But those who are against the research say that maybe the pills can change people’s memories and changing memories is very dangerous because memories give us our identity. They also help us all avoid the mistakes of the past.

"All of us can think of bad events in our lives that were terrible at the time but make us who we are. I'm not sure we want to wipe those memories out, "said Rebecca Dresser, a medical ethicist.

The passage is mainly about .

A. a new medical invention

B. a new research on the pill

C. a way of wiping out painful memories

D. an argument about the research on the pill

The drug tested on people can .

A. cause the brain to fix memories

B. stop people remembering bad experiences

C. prevent body producing certain chemicals

D. wipe out the emotional effects of memories

We can infer from the passage that .

A. people doubt the effects of the pills

B. the pill will certainly stop people's emotional memories

C. taking the pill will do harm to people's physical health

D. the pill has already been produced and used by the public in America

Which of the following does Rebecca Dresser agree with in the last paragraph ?

A. some memories can ruin people's lives.

B. people want to get rid of bad memories.

C. experiencing bad events makes us different from others.

D. the pill will reduce people's sufferings from bad memories.

You may probably read the passage in __________

A. a guidebook B. a textbook

C. a medical magazine D. a science fiction

_1.___There were few people on the earth, and natural resources seemed to be unlimited. Today things are different. The world has become too crowded. We are using up our resources too quickly, and at the same time we are polluting our environment with dangerous chemicals _2.__.

Everyone realizes today if too many fish are taken from the sea, there will soon be none left. Yet, with modern fishing methods, more and more fish are caught. We know that if too many trees are cut down, forests will disappear and nothing will grow in the land. Yet , we continue to use bigger and more powerful machines to cut down more and more trees. __3.__ However, in most countries waste products are still put into rivers or into the sea, and there are few laws to stop this. We know, too , that if the population of the world continues to rise, in a few years, there will not be enough food.www.zxxk.com

_4._ If we eat more vegetables and less meat, there will be more food available for everyone. Land that is used to grow crops feeds five times more people than land where animals are kept. __5._ the world population will not rise so quickly if people use modern methods of birth control. Finally, if we educate people to think about the problems, we shall have a better and cleaner planet in the future.

A. What can we do to solve these problems?

B. So we should try our best to protect the environment.

C. In the past, man didn’t have to think about the protection of his environment.

D. We realize that if the rivers are polluted with waste products from factories, we will die.

E. Why do some people do so foolish things?

F. If we continue to do this, human life won’t survive in the future.

G. Out natural resources will last longer if we learn to recycle them.

When an ant dies, other ants move the dead insect out. Sometimes, the dead ant get moved away very soon—within an hour of dying. This behavior is interesting to scientists, who wonder how ants know for sure—and so soon—that another ant is dead.

One scientist recently came up with a way to explain this ant behavior. Dong-Hwan Choe is a biologist. Choe found that Argentine ants have a chemical on the outside of their bodies that signals to other ants, “I’m dead—take me away.”

But there’s a twist to Choe’s discovery. Choe says that the living ants—not just the dead ones—have this death chemical. In other words, while an ant crawls around, perhaps in a picnic or home, it’s telling other ants that it’s dead.

What keeps ants from dragging away the living ants？Choe found that Argentine ants have two additional chemicals on their bodies, and these tell nearby ants something like, “Wait—I’m not dead yet.” So Choe’s research turned up two sets of chemical signals in ants: one says, “I’m dead,” and the other set says, “I’m not dead yet.”

Other scientists have tried to figure out how ants know when another ant is dead. If an ant is knocked unconscious, for example, other ants leave it alone until it wakes up. That means ants know that unmoving ants can still be alive.

Choe suspects that when an Argentine ant dies, the chemical that says “Wait-I’m not dead yet” quickly goes away. Once that chemical is gone, only the one that says “I’m dead” is left. “It’s because the dead ant no longer smells like a living ant that it gets carried to the graveyard, not because its body releases(释放) new unique chemicals after death,” said Choe. When other ants detect the “dead” chemical without the “not dead yet” chemical, they drag away the body.

Understanding this behavior may help scientists figure out how to stop Argentine ants from invading new places and causing problems. Choe would like to find a way to use the newly discovered chemicals to spread ant killer to Argentine ant nests.

The ants’ removal behavior is important to the overall health of the nest. “Being able to quickly remove dead individuals and other possible sources of disease is extremely important to all animals living in societies, including us,” says Choe. “Think about all the effort and money that we invest daily in waste management.”

1.The underlined word “twist” in Paragraph 3 means .

A．an unexpected change B．a clear mistake

C．an important key D．a shocking conclusion

2.Ants judge whether another one is dead or not depending on .

A．the sense of taste B．the sense of smell

C．the sense of touch D．the sense of sight

3.The result of the research can be used to .

A．kill troublesome pests

B．solve the problem of endangered species

C．prevent further expansion of the ants’ territory

D．keep the balance of nature

4.Why is it important to remove dead individuals?

A．Because it is easier to manage the living.

B．Because it can save money to deal with the waste.

C．Because it can provide more space for the living.

D．Because it can keep the living from suffering disease.

5.What might be the best title of the text?

A．Dead or living? It is easy to judge

B．Pulling away the dead ants is a difficult task

C．Ant nests have great undertaking capacity

D．Leaving it alone or taking it away? Ants feel puzzled

The research has caused a great deal of argument. Some think it is a bad idea, while others support it.

Supporters say it could lead to pills that prevent or treat soldiers' troubling memories after war. They say that there are many people who suffer from terrible memories. “Some memories can ruin people's lives. They come back to you when you don't want to have them in a daydream or nightmare. They usually come with very painful emotions,” said Roger Pitman, a professor of psychiatry at Harvard Medical School. “This could relieve a lot of that suffering.”

But those who are against the research say that maybe the pills can change people's memories and changing memories is very dangerous because memories give us our identity. They also help us all avoid the mistakes of the past.

“All of us can think of bad events in our lives that were terrible at the time but make us who we are. I'm not sure we want to wipe those memories out,” said Rebecca Dresser, a medical ethicist.

1.The passage is mainly about .

A. a new medical invention

B. a new research on the pill

C. a way of wiping out painful memories

D. an argument about the research on the pill

2.The drug tested on people can .

A. cause the brain to fix memories

B. stop people remembering bad experiences

C. prevent body producing certain chemicals

D. wipe out the emotional effects of memories

3.We can infer from the passage that .

A. experts are not sure about the effects of the pills

B. the pill will certainly stop people's emotional memories

C. taking the pill will do harm to people's physical health

D. the pill has already been produced and used by the American public

4.Which of the following does Rebecca Dresser agree with in the last paragraph?

A. Some memories can ruin people's lives.

B. People want to get rid of bad memories.

C. Experiencing bad events makes us different from others.

D. The pill will reduce people's sufferings from bad memories.

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