( A )

　　Every year there are changes in climate in different parts of the world. Some of these changes are due to natural causes. However, some climate changes are caused by air pollution and these changes may increase.

　　If the pollution affects the level of carbon dioxide(二氧化碳)in the atmosphere, the results are likely to be serious. Carbon dioxide has only a small part of the atmosphere. But it has an important function in keeping the balance between radiation from the sun entering the atmosphere and radiation leaving the earth. Some of the radiation is absorbed by the earth and some is radiated back into the atmosphere. The carbon dioxide in the atmosphere prevents some of the radiation from leaving the atmosphere. Thus the heat remains in the atmosphere and carbon dioxide helps to prevent the temperature of the earth from falling.

　　If the proportion(比例)of carbon dioxide in the atmosphere is increased as a result of air pollution, the temperature of the atmosphere may rise. This might cause the ice in the north and the south to melt. If this happened, the sea level could rise and parts of the earth would be flooded. This happening is not quite likely but the possibility exists.

　　There is also a fairly strong possibility that the dust level in the atmosphere will rise as the result of industrial pollution. This dust pollution will reflect sunlight back into space. If this happens less sunlight will reach the earth and the temperature will fall.

　　Another danger comes from the destruction of the earth's vegetation(植被)such as the forests of Brazil, which are being cleared away for farmland and cities. Trees use carbon dioxide and their destruction may upset the balance of carbon dioxide in the atmosphere.

　　1. The main purpose of this passage is to tell us that ________.

　　A. the climate of the world changed a lot

　　B. air pollution has never affected the climate of the world

　　C. carbon dioxide has nothing to do with climate changes

　　D. the climate of the world is affected by air pollution

　　2. From this passage we learn that carbon dioxide ________.

　　A. helps to prevent the temperature of the earth from rising

　　B. keeps much of the sun's radiation from entering the atmosphere

　　C. plays an important part in keeping the balance of the temperature of the earth

　　D. is not one of natural causes of climate changes

　　3. Judging from this passage, if the level of carbon dioxide in the atmosphere went down, the temperature of the earth would ________.

　　A. become higher

　　B. either rise or fall

　　C. become lower

　　D. neither rise nor fall

　　( B )

　　When I see an older woman driving a car, I can't help remembering the incident I met with when I first started driving. Let's see now. It was a rather nasty, rainy day: you know, one of those days when you wished you had stayed in bed instead. It was only my second day of driving and as you can imagine, I was scared stiff. I remember I had just turned a corner and had driven up to a stop light. While driving toward the intersection, the light suddenly turned red. The changing of the light came to me as a surprise and while thinking of what to do next I realized that I had bumped into the car in front of me. I just didn't stop soon enough. I just sat there for a moment. But as soon as I realized what I had done, I immediately got out of my car. Just as I was doing that, I saw a little old lady get out of the car in front of me and march towards me. I was really happy to see that no one was hurt. Well, she suddenly stopped, stared at me squarely in the face and said, "Listen, young man, how do you manage to stop your car when I'm not in front of you?"

　　4. What was the weather like on the writer's second day of driving?

　　A. Sunny and fair.

　　B. Snowy and nasty.

　　C. Wet and unpleasant.

　　D. Dry and windy.

　　5. What do you think of the old woman?

　　A. She was serious.

　　B. She was humorous.

　　C. She was cruel.

　　D. She was hard-hearted.

　　[答案与解析]

　　1. D。短文第一段最后一句表明了作者写本文的目的:一些气候变化是由空气污染造成的,而且气候变化还可能加大。2. C。短文第二段第三句说明了二氧化碳的功能:保持地球温度的平衡。3. C。第三段第一句即本题答案出处。如果空气污染造成大气中二氧化碳的比例上升,大气温度也会上升。反之,地球温度就会下降。注意本句的题干设置使用的是虚拟语气。4. C。通过对作者驾车途中的遭遇及第三句的提示,可得出此答案。 5. B。从短文的结尾句可以看出,老太太的问话是很幽默的。

　　(文/张荣；英语辅导报高三版2003-2004学年第45期；版权归英语辅导报社所有，独家网络合作伙伴新浪教育，未经许可，不得以任何形式进行转载。)