题目内容：
根据下面资料，回答题 Air Pollution
There was one thought that air pollution affected only the areas immediately around large citieswith factories and heavy automobile traffic. 26
On several occasions over the past decade, a heavy cloud of air pollution has covered the east ofthe United States and brought health warnings in rural areas away from any major concentration ofmanufacturing and automobile traffic. In fact, the very climate of the entire earth may be infected byair pollution.
Some scientists consider that the increasing concentration of carbon dioxide (二氧化碳)in theair resulting from the burning of coal and oil is creating a "greenhouse effect". It conserves heat reflected from the earth and raised the world' s average temperature. 27 Thus much of the polarice cap will melt and cities such as New York, Boston, Miami, and New Orleans will be in water.
28 This is a result that would be equally disastrous. A drop of just a few degrees couldcreate something close to a new ice age, and would make agriculture difficult or impossible in manyof our top farming areas.
Today we do not know for sure that either of these conditions will happen. 29 Driven byeconomic profit, people neglect the damage on our environment caused by the "advanced civilization". 30 But is it really worthwhile?
A. Perhaps, if we are lucky enough, the two tendencies will offset(抵销)each other and the world' stemperature will stay about the same as it is now.
B. If this view is correct, the world' s temperature is raised only a few degrees.
C. Maybe the air pollution is the price the human beings have to pay for their development.
D. At present, we realize that although these are the areas with the worst air pollution, the problem isliterally worldwide.
E. Lately, global warming is becoming a serious problem.
F. Another view, less widely held, is that increasing particular matter in the atmosphere (大气) isblocking sunlight and lowering the earth' s temperature.
第（26）题选
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