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 didn’t happen overnight. The problem of polluted air has been festering for centuries. Suddenly the problem of air pollut
It didn’t happen overnight. The problem of polluted air has been festering for centuries. Suddenly the problem of air pollut
admin
2012-05-18
36
问题
It didn’t happen overnight. The problem of polluted air has been festering for centuries.
Suddenly the problem of air pollution is becoming critical and is erupting right before our eyes. Not only do our eyes burn as they focus through murky air,but when the air clears,we see trees and vegetation dying. We must realize that this destruction can no longer be pinned to some mysterious cause. The one major culprit is air pollution.
Today’s air pollution is an unfortunate by-product of the growth of civilization. Civilized mall desires goods that require heavy industrialization and mass production. Machines and factories sometimes pollute and taint the air with substances that are dangerous to man and the environment. These substances include radioactive dust,salt spray,herbicide and pesticide aerosols, liquid droplets of acidic matter,gases, and sometimes soil particles. These materials can act alone to irritate objects and forms of life. More dangerously,they join together to act upon the environment. Only lately have we begun recognizing some of their dangerous consequences.
Scientists have not yet been able to obtain a complete report on the effects of air pollution on trees. They do know,however,that sulfur dioxide,fluorides,and ozone destroy trees and that individual trees re-spond differently to the numerous particulate and gaseous pollutants. Sometimes trees growing in a single area under attack by pollutants will show symptoms of injury or will die while their neighbors remain healthy. Scientists believe this difference in response depends on the kind of tree and its genetic makeup. Other factors,such as the tree’s stage of growth and nearness to the pollution source,the amount of pol-lutant,and the length of the pollution attack also play a part. In short, whether or not a tree dies as a result of air pollution depends on a combination of host and envimn-mental factors.
For the most part,air pollutants injure trees. To conifers,which have year-round needles,air pollution causes early balding. In this event,trees cannot maintain normal food production levels. Undernourished and weakened, they are open to attack by a host of insects,diseases,and other environmental stresses. Death often follows.
Air pollution may also cause hardwoods to lose their leaves. Because their leaves are borne only for a partion of the year and are replaced the following year,air pollution injury to hardwoods may not be so severe.
The author attributes today’s air pollution to_____.
选项
A、the growth of civilization
B、man’ s carelessness
C、environmental imbalance
D、some mysterious cause
答案
A
解析
题目问:作者把今天的空气污染归因于什么?第三段“Today’s air pollution,is an unfortunate by-product of the growth of civilization。”通过这句话可知,当今的空气污染是人类文明发展过程中的一个不良副产品。据此判断,应选择A。
转载请注明原文地址:https://jikaoti.com/ti/xxbYFFFM
0
考博英语
相关试题推荐
GrandTetonNationalPark______themostscenicportionoftheglaciated,snow-coveredTetonRange.
Theaimofeducationorcultureismerelythedevelopmentofgoodtasteinknowledgeandgoodforminconduct.Theculturedman
Imagineanaccidentinwhichanuclearpowerplantreleasesradioactivegas.Thecloudstartsmovingwiththewind.Clearly,the
(Itshardlyevernecessary)toaskahungryboy(tocometo)dinnertwicebecausehe(hasahearty)appetitethat(getshimto)
Growingeconomicproblemswere______byadeclineinoiloutput.
Giventhechoicebetweenspendinganeveningwithfriendsandtakingextratimeforhisschool-work,AndyKliseadmitshewould
GeorgeMasonmustrankwithJohnAdamsandJamesMadisonasoneofthethreeFoundingFatherswholefttheirpersonalimprinton
Theboardofdirectorshavealreadydiscussedthesubject______inthepreviousmeetingsandtheywillhandleitinallitsaspe
Untilrecently,such______waslimitedtotelephonequestionsandanswersmuchlikedaytimetalkshows.
Anypersonwhoisin______whileawaitingtrialisconsideredinnocentuntilhehasbeendeclaredguilty.
随机试题
A.输血前肌内注射异丙嗪25mgB.输血前输入少量等渗盐水C.输血1000ml应静脉注射10%葡萄糖酸钙D.皮下注射0.1%肾上腺素1mlE.热敷双侧腰部,保护双肾输血时为防止过敏反应的发生应
A.约束纵行诸经B.加强了十二经脉中相为表里的两经在体表的联系C.加强了十二经脉中相为表里的两经在体内的联系D.调节十二经脉的气血E.分主一身左右之阴阳剐络的生理功能为
铜期货市场出现反向市场的原因可能有( )。
编制合并财务报表时,母公司对本期增加的子公司进行的下列会计处理中,正确的有()。
赵某、钱某、孙某、李某拟发起设立北方股份有限公司(以下简称北方公司),初步拟订的公司章程包括以下内容:①注册资本2000万元,其中赵某、钱某共以货币600万元出资;孙某以实物作价出资,绎评估机构评估为800万元;李某以其专利技术出资,作价600万元。因为资
A旅行社与B饭店在旅游合同中都没有按照合同约定履行义务,对此,()违约责任。
对于获得知识的理解,认为主要有“亲知”“闻知”和“说知”三种途径的思想家是我国古代的()。
一、注意事项 1.申论考试,与传统作文考试不同,是对分析驾驭材料的能力与对表达能力并重的考试。 2.作答参考时限:阅读资料40分钟,作答110分钟。 3.仔细阅读给定的资料,按照后面提出的“申论要求”依次作答,答案书写在指定位置。二、资料
Dotryyourbesttofinishit,______you?
上海自由贸易区(FreeTradeZone,FTZ)于2013年9月开园。建立自贸区是中国改革开放新时代的一个重要决定。自贸区位于上海市的郊区,面积为28.78平方公里。它的建立旨在探索新途径,以减少政府干预和向全球投资者(investor)更广泛地开
最新回复
(
0
)