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
2016-01-30
43
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 man 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 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 environment factors.
For the most part, air pollutants injury 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, disease, 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 portion 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
细节事实题。根据题干关键词today’s air pollution定位到原文第三段首句。原句中的the growthof civilization与选项A对应。故答案为A。
转载请注明原文地址:https://kaotiyun.com/show/J2GO777K
0
考博英语
相关试题推荐
Peopleappeartobeborntocompute.Thenumericalskillsofchildrendevelopsoearlyandsoinexorablythatitiseasytoimag
Awayfromtheirprofession,scientistsareinherentlynomorehonestorethicalthanotherpeople.Butintheirprofessionthey
AreweatthebeginningofanotherAgeofExploration?Perhapsevenmoreimportant,areweatthebeginningof【C1】______AgeofC
AreweatthebeginningofanotherAgeofExploration?Perhapsevenmoreimportant,areweatthebeginningof【C1】______AgeofC
Whowouldhavethoughtwewouldbecomeaplanetof"ologies"?There’sbiology,psychology,herpetology,etymology,andgeologyj
Whowouldhavethoughtwewouldbecomeaplanetof"ologies"?There’sbiology,psychology,herpetology,etymology,andgeologyj
Agreatdealofattentionisbeingpaidtodaytotheso-calleddigitaldivide—thedivisionoftheworldintotheinfo(informatio
Stanleywas______bywhatIhadsaidandwhenIrealizedthis,Iapologizedtohimforbeingsotactless.
Idecidedtogetintouchwithhim______afterIreceivedhisletter.
Alittlemorethanacenturyago,MichaelFaraday,thenotedBritishphysicist,managedtogainaudiencewithagroupofhighgo
随机试题
“曾子以子游之言告於有子”中“於”的用法是
用做衡量组织兴奋性高低的指标通常是
麻疹患者的皮疹最先出现的部位是
女性患者,37岁,近10d来发热,体温最高在38.5℃,多在午后出现。伴咳嗽,多为干咳。应用青霉素治疗1周,不见好转。不除外支原体肺炎与早期继发性肺结核,鉴别诊断上下列哪项检查最重要
不属于猪营养状况评价指标的是
下列哪项因素有利于创伤掺复和伤口愈合
固体根据燃点的高低分为可燃固体和易燃固体,其中易燃固体按其燃点高低、燃烧速度快慢、放出气体的毒害性大小分为()。
某大型石油化工公司开展QC小组活动已经有5年,为了保证成立的小组都能获得良好的业绩,公司质量管理部作为该项活动的管理部门,希望注册的小组都要进行初选。对那些主要由工人组成、没有技术人员参加的小组,以及选题太小、预期经济效益不高的小组就筛选掉,从而保证该企业
下列不属于我国专门法治队伍的是()。
“飞歌”是最具代表性的一种壮族民歌。()
最新回复
(
0
)