Weather changes when the temperature and the amount of water in the atmosphere change. We can see and feel water coming from the atmosphere when we have rain. But the water must somehow get back to the atmosphere. Meteorologists call this the water cycle.

   There are many stages in the water cycle. Rain falls when water vapor in clouds condenses(凝结). Drops of water form and fall to the ground. The water soaks into the ground and feeds streams and rivers. A lot of rain falls into the sea. The heat of the sun evaporates some of the water in the ground and in the rivers, lakes, and the sea. It changes the liquid water into water vapour. The vapour rises onto the air. Water vapour is normally invisible. On a very damp or humid day, however, you can sometimes see water vapour rising from a puddle(水坑) or pond in a mist(薄雾) above the water. Water vapour also gets into the air from living things. Trees and other plants take in water through their roots and give off water vapour from their leaves. People and land animals drink water and breathe out water vapour. In all these ways the water returns to the air. There it gathers to form clouds and condenses to form rain. The rain falls to earth, and the cycle starts again. It continues even if snow or hail(冰雹) fall instead because both eventually melt to form water. The amount of water vapour in the air depends on the temperature. The air is more moist(潮湿) in the tropics(热带) than in the cold polar regions.

What is the main idea of the passage?

A. Water cycle.                                  

B. Water vapour.

C. How rain forms.                  

D. Water, vapour, rain.

How many ways of the water returning to the air are discussed in the text?

A. Two.                   B. Three.        C. Four.       D. Five.

Whether water vapour can be seen or not depends on _______.

A. how much water is evaporated          

B. how good your eyes are

C. in which way water is evaporated        

D. climate or weather

From the passage we get to know _______.

A. there is more water vapour in the air in the tropics than in cold polar regions

B. there is more water vapour in the air in cold polar region than in the tropics

C. it gets more rain in the tropics than in cold polar regions because there is less vapour

D. the amount of water vapour in the air depends on how often it rains

There are many commonly held beliefs about eyeglasses and eyesight that are not proved facts. For example, some people believe that wearing glasses too soon weaken the eyes. But there is nothing to show that the structure (结构) of eyes is changed by wearing galsses at a young age. Wearing the wrong galsses, however, can prove harmful. Studies show that only children can develop loss of sihgt if they have the wrong glasses. We have all heard some of the common myths(荒诞的说法)about how eyesight get bad. Too little light makes the eyes work harder, so they do get tired and strained (过劳). Eyestrain also resulsts from reading a lot, reading in bed, and watching too much television. But, although eyestrain may cause some pain or headaches, it does not harm eyesight all the time. Another myth about eyes is that they can be replaced from one person to another . It is quite difficult to connect aneyeball to a new brain.And it is impossible to replace a whole eyeball to a new person. Only certain parts of the eye can be replaced now. But if we keep clearing up the myths and learning more about the eyes, some day it may be possible to replace a full eyeball.

1.

One cause of eyestrain mentioned in the passage is ____.        .

2.

.From this passage one can conclude that    ____.   .

3.

"Commonly held beliefs" are ____.       .

4.

This passage mainly tells us that ____.

When we can see well, we do not think about our eyes often. It is only when we can not see perfectly that we come to see how important our eyes are.

People who are nearsighted can only see things that are very close to their eyes. Many people who do a lot of close work, such as writing and reading, become nearsighted. Then they have to wear glasses in order to see distant things clearly.

People who are farsighted face just the opposite problem. They can see things that are far away, but they have difficulty reading a book unless they hold it at arm’s length. If they want to do much reading, they must get glasses too.

Other people do not see clearly because their eyes are not exactly the right shape. This, too, can be corrected by glasses. Some people’s eyes become cloudy because of cataracts. Long ago these people often became blind. Now, however, it is possible to operate on the cataracts and remove them.

When night falls, colors become fainter to the eyes and finally disappear. After your eyes have grown used to the dark, you can see better if you use the side of your eyes rather than the centers. Sometimes, after dark, you see a small thing to one side of you, which seems to disappear if you turn your head in its direction. This is because when you turn your head, you are looking at the thing too directly. Men on guard duty sometimes think they see something moving to one side of them. When they turn to look straight at it, they can not see it any more, and they believe they were mistaken. However, this mistake happens because the center of the eye, which is very sensitive in daylight, is not as sensitive as the sides of the eye after dark.

59. We don’t know that our eyes are of great importance until ________.

A. we think about our eyes           B. we cannot see clearly

C. we wear glasses                 D. we have to do much reading

60. According to the passage, a ________ is more likely to be nearsighted.

A. student    B. runner    C. guard    D. worker

61. People who are farsighted ________ .

A. cannot do a lot of close work without glasses

B. can only see things that are very close to their eyes

C. have difficulty reading a book if they hold it at arm’s length

D. have the same problem as the nearsighted people

62. To see a small thing at night, it is better to look ________ .

A. with wide open eyes             B. with half shut or narrowed eyes

C. straight at it                    D. in a slightly different direction

_____________ on the portrait, mother was deep in thought.

There are robots all around us. Some do very complicated jobs like flying airplanes and driving subway trains. and some do one simple job. When an automatic washing machine is switched on, water pours in. The machine waits until the water is warm enough for washing clothes. It does this by “feedback”(反馈). Information about what is happening is feedback into the robot to tell what to do next. Our eyes, ears and other senses are our feedback. They tell us what is going on around us. So robots are like human beings in two ways.

They work and they have feedback.

In some ways robots are better than human beings. They work quickly and do not make mistakes. They do not get bored doing the same job over and over again. And they never get tired. So robots are very useful in factories. They can be taught to do many different jobs. First their electronic brain must be shown how the job is done. A person moves the robot’s “arms” and “hands” through each part of the job.

The most intelligent robots can move and see. Their eyes are cameras. Their fingers can feel shapes and sizes of the objects. These robots have computer brains linked to their eyes and fingers, which control their actions. The expensive robots are used in scientific research. They do such job as handling radioactive materials.

In this passage the author tells us that ________.

A. robots are very popular

B. there are various kinds of robots

C. we see robots only at certain times

D. robots can be easily controlled

What does the author seem to inform you about robots?

A. They should be greatly improved.

B. They will probably take over in the future.

C. They are very helpful and useful to humans.

D. They are machines that break down a lot.

The author says that in industry ________.

A. robots break down a lot    

B. robots can do many jobs

C. robots only get in the way

D. robots sometimes cause troubles

The fact that a robot never gets bored doing the same job means that _______.

A. it is very much like human beings

B. it can do boring jobs for people

C. it will never bore people

D. it will work much better than human beings

The robots used for scientific research _______.

A. are not very clever     

B. are very cheap

C. are very big

D. are very costly