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
2015-06-23
76
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,丈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/f3l7777K
0
大学英语四级
相关试题推荐
A、Heorganisesinternationalflightsfortourists.B、Hetravelsaroundtheworldwithcheaptickets.C、Hedeliverspapersandpa
汉语是中国汉民族使用的语言,汉语历史悠久,在3,000多年前就有了相当成熟的文字。汉语有超过12亿的使用者,是使用人数最多的语言之一,除了中国,新加坡、马来西亚等国也有相当一部分人使用汉语,分布在世界各地的几千万华侨、华裔,也以汉语的各种方言为自己的母语。
A、Sendflowerstosomeoneinhospital.B、Deliverapackagetothehospital.C、Arrangesomeflowers.D、Talktoadoctor.A对话中男士说他
Forthispart,youareallowed30minutestowriteashortessay.Youshouldstartyouressaywithabriefdescriptionofthepi
A、Theyarereadonthecomputerscreen.B、TheyarepublishedinEuropeanlanguages.C、Theyarebroadcastontelevisionandther
ThefamilyinBritainischanging.TheoncetypicalBritishfamilyheadedbytwoparentshasundergone【B1】______changesduringt
Gesturesarethesilentlanguageofeveryculture.Itisimportanttoknowthebodylanguageofeverycountry,orwemaybe【B1】_
A、Becausesheneedsnoticehimwhenthebookisavailable.B、Becauseitistheregistrationrequirementofthelibrary.C、Becaus
HaitiDreamsofTourismRevivalA)LikemanyofitsCaribbeanneighbors,Haitioncedrewmanytourists.Butdecadesofpolitical
TheUnitedStates’predominanceinscienceandtechnologyisfading,areportreleasedthismonthbytheNationalScienceBoard
随机试题
分析达维多定律。
其诊断为其治法为
下列表述中属于证的是
下列各项有关危险化学品的主要危险特性的说法不正确的是()。
掺入适量的缓凝剂能使混凝土()。
SDH设备光接收机灵敏度和最小过载光功率的测试仪器有()。
童年期又称学龄初期,相当于_________阶段。
,()。
“战国七雄”指的是______。
A19thCenturyKillerDisease:TuberculosisIn1882,RobertKoch,aGermancountrydoctor,succeededinisolatingthebacill
最新回复
(
0
)