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
2017-08-23
20
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 "greenhouse effect" results from________.
选项
A、the concentration of carbon dioxide in the air
B、the increasing particulate matter in the atmosphere
C、the burning of firewood
D、the blocking of sunlight
答案
A
解析
由题干中“‘greenhouse effect’results from”可以定位到文中第二段第一句话。该句提到一些科学家觉得因为燃烧化石燃料(煤和石油),空气中聚集了越来越多的二氧化碳,产生了“温室效应”。
转载请注明原文地址:https://jikaoti.com/ti/LsjFFFFM
0
大学英语四级
相关试题推荐
A、Heistimid.B、Heisheroic.C、Heisdangerous.D、Heisclumsy.B男士首先用reallysomething“真了不起”评价Victor,然后具体例证:为了救落水儿童险些丧命。女士补充说:
Corporationsasagroupofferavarietyofjobs.Mostlargecompaniessendpeopletocollegesto【B1】______graduatingstudentsw
A、Amanager.B、Anofficial.C、Adriver.D、Apostalclerk.C女士说:“请在曼哈顿邮局让我下车。”男士回答说:“哦,有1个小时的车程呢。何不……?”可见女士是在车上和司机说话,C正确。关键词drop和
Youngpeoplelegallybecomeadultsattheageof18.Theycan【B1】______andsigncontracts.Butadulthoodismorethanalegal【B
Youngpeoplelegallybecomeadultsattheageof18.Theycan【B1】______andsigncontracts.Butadulthoodismorethanalegal【B
Youcantelltheageofatreeby【B1】______itsrings,buttheserecordsofatree’slifereallysayalotmore.Scientistsare
据统计,全国共有超过6100万留守儿童(left-behindchildren)。他们的父母远离家乡到城镇地区谋生,留下他们由祖父母或其他亲戚照顾。留守儿童问题是一个值得关注的社会问题。留守儿童无法像同龄孩子那样得到父母的关爱,从而引起各种心理问题。此外
Althoughthestigma(耻辱)onceassociatedwithmentalillnesshasgraduallygoneawayinrecentyears,mostoftheAmericanswhoha
ProfessorSmithrecentlypersuaded35people,23ofthemwomen,tokeepadiaryofalltheirabsent-mindedactionsforafortnig
随机试题
建筑产品具有固定性、多样性、________和生产周期长等特点。
房地产项目按比较定价法制定的价目表,其步骤如下()。
若部分杆件相对线刚度如下:四层梁i=0.65;三层梁i=0.98;二层梁i=1.0。四层柱i=0.58;三层柱i=0.60;二层柱i=0.61。则四层柱DE的K=______。
张某和妻子李某2016年收入如下:(1)张某2016年3月领取个体户营业执照,经营汽车零件加工,当年取得生产经营收入100万元,生产经营成本为48万元,含子女的生活费支出8万元、从业人员工资8万元、张某本人的工资12万元、企业发生的与生产经营和家庭生活难
下列各句中,划线的成语使用不恰当的一项是()。
一、注意事项1.申论考试是对应考者阅读理解能力、综合分析能力、提出和解决问题能力、文字表达能力的测试。2.作答参考时限:阅读资料40分钟,作答110分钟。3.仔细阅读给定资料,按照后面提出的“申论要求”依次作答。二、给定资料
甲:王经理是大众汽车集团在中国的高级雇员之一。乙:怎么可能?王经理一直用丰田汽车。上述对话中,乙的陈述隐含的一个前提是()。
InAmericaalone,tippingisnowa$16billion-a-yearindustry.Arecentpollshowedthat40%ofAmericans【C1】______thepractice
Amysteriousphenomenonistheabilityofover-watermigrantstotraveloncourse.Birds,bees,andotherspeciescankeeptrack
TheancientGreeksexplained______.Whichofthefollowingstatementsistrueaccordingtothepassage?
最新回复
(
0
)