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
The long, wet summer here in the northeastern U.S.notwithstanding, there’s a world shortage of pure, fresh water.As demand for w
The long, wet summer here in the northeastern U.S.notwithstanding, there’s a world shortage of pure, fresh water.As demand for w
admin
2015-05-29
67
问题
The long, wet summer here in the northeastern U.S.notwithstanding, there’s a world shortage of pure, fresh water.As demand for water hits the limits of finite supply, potential conflicts are brewing between nations that share transboundary freshwater reserves.
Many people ask why we cannot simply take it from the sea, using our sophisticated technology of desalinization.But a good water supply must be hygienically safe and pleasant tasting and water containing salt would corrode machinery used in manufacturing in addition to producing chemical impurities.Since more than 95% of our water sits in the salty seas, man is left to face the reality that most water on the surface of the earth is not available for us.
One very feasible way of sustaining our supply of freshwater is to protect the ecology of our mountains.Mountains and water go together, a fact to which Secretary General Kofi Annan has drawn attention more than once.From 30% to 60% of downstream fresh water in humid areas and up to 95% in arid and semi-arid environments are supplied by mountains.Without interference nature has its own way of purifying water-even though chlorination and filtration are still necessary as a precaution.In a mountainous area, aeration, due to turbulent flow and waterfalls, causes an exchange of gases between the atmosphere and the water.Agriculture, industry, hydroelectric generators and homes that need water to drink and for domestic use depend on these resources and, thus, we must protect mountainous areas as a means of survival.
By saying that nature "has its own way of purifying water" (Line 5, Para.3) the author is referring to______.
选项
A、aeration
B、filtration
C、chlorination
D、absorption
答案
A
解析
本题中大自然净化水源的方式指的是后文提到的充气。因此A项为正确答案。
转载请注明原文地址:https://kaotiyun.com/show/RYLO777K
0
考博英语
相关试题推荐
Inmanycountriesnow,smokingisnot______inpublicplaces.
Investmentinthepublicsector,suchaselectricity,irrigation,quarrying,publicservicesandtransport(excludingvehicles,
Opinionpollsarenowbeginningtoshowanunwillinggeneralagreementthat,whoeveristo【21】andwhateverhappensfromnowon,
Inapurelybiologicalsense,fearbeginswiththebody’ssystemforreactingtothingsthatcanharmus—theso-calledfight-o
Youmighthavetogobacktotheinitialepochprintingpresstofindapublishingtechnologyasdisruptive.Theinternetcanre
Scientists,thosewhoareendowedwithpeculiarcapabilityofthinkingandanalysisandwithendlesspatienceinobservingandda
Mostofustellonetwoliesaday,accordingtoscientistswhostudythesethings.Andwerarelygetcaught,becausetheliesw
充分发挥个体、私营等非公有制经济在促进经济增长、扩大就业和活跃市场等方面的重要作用。放宽国内民间资本的市场准入领域,在投融资、税收、土地使用和对外贸易等方面采取措施,实现公平竞争。依法加强监督和管理,促进非公有制经济健康发展。完善保护私人财产的法律制度。
A、expectingB、hopingC、wishingD、dreamingB本题考核的知识点是动词。四个词都有“希望“的意思,但其程度及用法不同。A项表示“希望,期待”,后面不用加介词;B项表示“希望”;C项表示“很难达到的希望”;D项表示“梦想
Tight-lippedeldersusedtosay,"It’snotwhatyouwantinthisworld,butwhatyouget."Psychologyteachesthatyoudogetwh
随机试题
关于硅酸盐水泥及普通水泥的技术性质表述不正确的是()。
装配中常用的定位方法有哪些?
一个测验能测验出它所要测量的属性和特点的程度,叫作测验的()
A.狭窄性腱鞘炎B.类风湿关节炎C.髌骨软化症D.腰椎间盘突出症男,26岁,腰腿痛1年,查体:脊柱侧凸畸形,直腿抬高试验及加强试验阳性,左小腿外侧感觉减弱,诊断是
关于优先股的说法,正确的是()。
锅炉省煤器使用的管子一般采用()。
如图,直线l对应的函数表达式为().
根据《合伙企业法》规定,有限合伙人()(2014年一专一第46题)
A.acceptB.unquantifiableC.useD.whatE.purchasedF.consumedG.encouragedH.climbingI.predictablyJ.actually
Thenightmareofyourmobilephonerunningoutofpowermid-conversationcouldbeover,forresearchersattheUniversityofWis
最新回复
(
0
)