14．It was once thought that air pollution affected only the area immediately around large cities with factories and/or heavy automobile traffic．Today，we know that although these are the areas with the worst air pollution，the problem is actually 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 world's average temperature．If this view is correct and the world's 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 （废气排往空中而形成的微粒、颗粒）matter in the atmosphere is blocking sunlight and lowering the earth's 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 willoffset each other and the world's temperature will stay about the same as it is now．
32．As pointed out at the beginning of the passage，people used to think that air pollutionD．
A．caused widespread damage in the countryside
B．affected the entire eastern half of the United States
C．had damaging effects on health
D．existed merely in urban and industrial areas
33．The underlined word"offset"in Para．2 could best be replaced byB．
A．slip into
B．make up for
C．set up
D．catch up with
34．It can be inferred from the passage thatA．
A．lowering the world's temperature merely a few degrees would lead many major farming areas to disaster
B．raising the world's temperature only a few degrees would not do much harm to life on earth
C．almost no temperature variations have occurred over the past decade
D．the world's temperature will remain constant in the years to come
35．This passage is mainly concerned withC．
A．the greenhouse effect
B．the burning of fossil fuels
C．the potential effect of air pollution
D．the likelihood （可能性） of a new ice age．
分析 通读全文可知，本文介绍了空气污染可能导致的后果．空气污染可能会带来的两种不同的后果，一些人认为全球温度会上升，另一些人认为温度会下降，如果我们幸运的话，这两种可能性可以相互弥补．
解答 32：D 细节理解题．根据第一段中的"It was once thought that air pollution affected only the area immediately around large cities with factories and/or heavy automobile traffic．"可知，空气污染只存在于大城市里，故选D．
33：B 词义猜测题．上文讲述了空气污染可能会带来的两种不同的后果，一些人认为全球温度会上升，另一些人认为温度会下降，如果我们幸运的话，这两种可能性可以相互弥补，故选B．
34：A 细节理解题．根据最后一段中的"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．"可知，世界上气温降低几度就会导致农业上的灾难，故选A．
35：C 主旨大意题．本文介绍了空气污染可能导致的后果，空气污染可能会带来的两种不同的后果，一些人认为全球温度会上升，另一些人认为温度会下降，如果我们幸运的话，这两种可能性可以相互弥补．故选C．
点评 阅读理解题测试考生在阅读基础上的逻辑推理能力，要求考生根据文章所述事件的逻辑关系，对未说明的趋势或结局作出合理的推断；或根据作者所阐述的观点理论，对文章未涉及的现象、事例给以解释．考生首先要仔细阅读短文，完整了解信息，准确把握作者观点．
