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
2015-01-09
31
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 respond 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 pollutant,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 envimnmental 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://kaotiyun.com/show/GdQO777K
0
考博英语
相关试题推荐
TheUnitedNationsdeclaredlastFridaythatSomalia’sfamineisover.Buttheofficialdeclarationmeanslittletothemillions
TheUnitedNationsPopulationFundhaspickedOctober31asthedaytheworldwillbehometo7billionpeople.Forbettera
(1)AgiftedAmericanpsychologisthassaid,"Worryisaspasmoftheemotion;themindcatchesholdofsomethingandwillnotle
ThefieldofsociologyintheUnitedStatesdevelopedasaresultofasocialexperiencewhichhadverylittletodowiththepo
Theprincipleofthesocialcharacteroftheschoolasthebasicfactorinthemoraleducationgivenmaybealsoappliedtothe
Theprincipleofthesocialcharacteroftheschoolasthebasicfactorinthemoraleducationgivenmaybealsoappliedtothe
Justiceinsocietymustincludebothafairtrialtotheaccusedandtheselectionofanappropriatepunishmentforthoseproven
Isitproperforthegovernmentto______publicopinionthroughself-serving,one-sidedjournalism?(厦门大学2006年试题)
Thatparkcontains______reproductionsofsuchfamoussightsinChinaastheGreatWallandtheSummerPalace.
随机试题
财政局干部李某在机关外兼职。关于李某兼职,下列说法中正确的是()。
回归分析在具体研究变量之间的回归关系时,一般最后一步是
葛根的适应症有
A.水钠潴留B.促红细胞生成素减少C.活性维生素D3减少D.出血倾向E.含氮代谢产物潴留
市场经济的基本特征反映了市场经济的基本属性,即自由生产、自由决策、自由流动、自由分配,可以说市场经济的本质是()。
下列有关金融资产减值损失的处理中,表述正确的有()。
下列业务中,应当按照“邮电通信业"税目缴纳营业税的是()。
甲与乙签订了一份房屋装修合同,在履行合同过程中发生纠纷。甲向律师丙咨询。丙认为根据合同法,乙的行为构成违约,如提起诉讼,有较大胜诉把握。丙的分析体现法的作用是()。①预测作用②评价作用③强制作用④教育作用
在考生文件夹下有一个数据库文件“samp3.aeedb”,里面已经设计了表对象“tEmp”、窗体对象“fEmp”、宏对象“mEmp”和报表对象“rEmp”。同时,给出窗体对象“fEmp”的“加载”事件和“预览”及“打印”两个命令按钮的单击事件代码,请按以下
WhatdidMikedotoendhisnormalanddulllife?
最新回复
(
0
)