不谈定的温度

周波

Directions：Read the following passage. Answer the questions according to the information given in the passage and the required words limit.

It was once thought that air pollution affected only the area immediately around large cities with factories and heavy automobile traffic. Today，we know that although these are the areas with the worst air pollution，the problem is literally worldwide. On several occasions over the past decade，a heavy cloud of air pollution has covered the entire eastern half of the United States and led to health warnings even in rural areas away from any major concentration of manufacturing and automobile traffic. In fact，the very climate of the entire earth may be affected by air pollution. Some scientists feel that the increasing concentration of carbon dioxide in the air resulting from the burning of fossil fuels（coal and oil）is creating a“greenhouse effect”—holding in heat reflected from the earth and raising the worlds average temperature. If this view is correct and the worlds temperature is raised only a few degrees，much of the polar ice cap will melt and cities such as New York，Boston，Miami，and New Orleans will be under water.

Another view，less widely held，is that increasing particulate matter in the atmosphere is blocking sunlight and lowering the earths temperature—a result that would be equally disastrous. A drop of just a few degrees could create something close to new ice age and would make agriculture difficult or impossible in many of our top farming areas. At present we do not know for sure that either of these conditions will happen（though one recent government report prepared by experts in the field concluded that the greenhouse effect is very likely）. Perhaps，if we are very lucky，the two tendencies will offset each other and the worlds temperature will stay about the same as it is now.

1. Where did people think air pollution exist merely？（No more than 11 words）

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2. According to the text，what caused the“greenhouse effect”？（No more than 16 words）

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3. What will happen if the worlds temperature is raised only a few degrees？（No more than 17 words）

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4. What is the best result about the matter of the worlds temperature in the eyes of the author？（No more than 10 words）

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参考答案

1. Merely in urban and industrial areas. / The area around large cities with factories and heavy automobile traffic.

2. The increasing concentration of carbon dioxide in the air resulting from the burning of fossil fuels.

3. Much of the polar ice cap will melt and some big coastal cities will be under water.

4. It will stay about the same as it is now. / It will neither rise nor drop.

编辑/梁宇清