首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
It was once thought that air pollution affected only the area immediately around large cities with factories and heavy automobil
It was once thought that air pollution affected only the area immediately around large cities with factories and heavy automobil
admin
2013-11-21
33
问题
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 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 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 will offset each other and the world’s temperature will stay about the same as it is now.
The passage is mainly about______.
选项
A、the potential effect of air pollution
B、the possibility of a new ice age
C、the effects of global warming
D、the causes of climate change
答案
A
解析
主旨题。综观全文,文章主要讲述了空气污染可能造成的严重后果。选项B、C均只概括了文章的部分内容,D项文章未提到。故答案为A。
转载请注明原文地址:https://kaotiyun.com/show/NkS7777K
0
大学英语四级
相关试题推荐
A、HethoughtArtwasuseless.B、Hewasofferedajobinabigaccountingfirm.C、HewantedtogotoLondontostudyArt.D、Hewa
WhatisanElNinoAnElNinoisatemporarychangeintheclimateofthePacificOcean,intheregionaroundtheequator.Y
WhatisanElNinoAnElNinoisatemporarychangeintheclimateofthePacificOcean,intheregionaroundtheequator.Y
WhatisanElNinoAnElNinoisatemporarychangeintheclimateofthePacificOcean,intheregionaroundtheequator.Y
WhatisanElNinoAnElNinoisatemporarychangeintheclimateofthePacificOcean,intheregionaroundtheequator.Y
WhatisanElNinoAnElNinoisatemporarychangeintheclimateofthePacificOcean,intheregionaroundtheequator.Y
A、Shefeltitwastiring.B、Shefeltitwasverynice.C、Shethoughtittooklesstime.D、Shethoughtitwasexpensive.BM:Did
Newsagencyisalsocallednewsservice【B1】______,whichcollects,writes,anddistributesnewsfromaroundanationortheworl
Newsagencyisalsocallednewsservice【B1】______,whichcollects,writes,anddistributesnewsfromaroundanationortheworl
随机试题
FewwoulddisputethattheLansleyreformsoftheNationalHealthServiceinEngland,embodiedintheHealthandSocialCareAct
建设工程监理管理服务的内涵不包括()。
当事人一方有权请求人民法院或者仲裁机构变更或撤销的合同有( )。
股票和债券是直接投资工具,筹集的资金主要是投向实业领域;而证券投资基金是一种间接投资工具,所筹集的资金主要投向有价证券等金融工具。()
关于增长量的说法,正确的有()。
南海公司计划用新设备替换旧设备。旧设备预计尚可使用5年,目前变现净收入为60000元。新设备投资额为150000元,预计使用5年。至第5年末,新、旧设备的预计残值假设分别为10000元和6000元(各残值与税法的规定相同)。使用新设备可使企业在未来5年
电磁波属于横波,而不属于纵波。()
随着环境、教育和实践活动的作用,人的遗传素质会逐渐地发生变化。这说明遗传素质具有可塑性。()
我国的多党合作制是()。
[*]
最新回复
(
0
)