首页
登录
职称英语
It didn’t happen overnight. The problem of polluted air has been festering f
It didn’t happen overnight. The problem of polluted air has been festering f
游客
2025-04-12
23
管理
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. [br] The author implies that the greatest source of pollution is____.
选项
A、heavy industry
B、chemical processing plants
C、urban expansion
D、salt spray
答案
A
解析
题目问:作者暗示,最大的污染源是什么?第三段第二句“Civilized mall desires goods that requireheavy industrialization and mass production”,通过这句话可知,生产商品需要重工业的支持,伴随而来的就是环境污染。据此判断,应选择据此A.
转载请注明原文地址:https://tihaiku.com/zcyy/4034487.html
相关试题推荐
(中国矿业大学2009年试题)Solvingaproblemcanbebrokenintoseveralsteps.First,t
(中国矿业大学2009年试题)Solvingaproblemcanbebrokenintoseveralsteps.First,t
(中国矿业大学2009年试题)Solvingaproblemcanbebrokenintoseveralsteps.First,t
(中国矿业大学2009年试题)Solvingaproblemcanbebrokenintoseveralsteps.First,t
(中国矿业大学2009年试题)Solvingaproblemcanbebrokenintoseveralsteps.First,t
(中国矿业大学2009年试题)Solvingaproblemcanbebrokenintoseveralsteps.First,t
Theproblemofwherewewillraisethefundsfortheschemehasnotyetbeen____
Bigcitiestodayareconfrontedwithveryseriousproblems.Transportisa【C
Bigcitiestodayareconfrontedwithveryseriousproblems.Transportisa【C
Bigcitiestodayareconfrontedwithveryseriousproblems.Transportisa【C
随机试题
在中美两国政府的共同支持下,美国的学校开始在语言教学大纲巾增设汉语——这个世界上使用人数多但同时也是最难学的语言之一。在2400所学校表示有兴趣之后,将
[originaltext]M:NowI’lltakesomequestions.W:Well,Mr.Brown,Ihaveaque
There’snobetterfeelinginajobthanwhenyouknowthebosshasfullconf
下列哪两种抗菌药物合用可获得协同作用A.青霉素+氯霉素 B.青霉素+四环素
患者,男性,70岁。排尿犹豫,夜尿增多,与家人饮烈性酒后,小便不能自解,体检发现
山楂的各种饮片中,长于活血化瘀的是A.生山楂B.炒山楂C.焦山楂D.山楂炭E.麸
重力式挡土墙如图8所示,挡土墙底面与土的摩擦系数μ=0.4,墙背与填土间摩擦角=
陶行知教育思想的核心是( )A.生命教育 B.生活教育 C.教育即生活
根据《环境影响评价技术导则地表水环境》,环境质量评价标准的依据不包括()。
施工单位承包某外资工程的施工,与业主签订的承包合同约定:工程合同价2000万元;
最新回复
(
0
)