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
79
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
Comparisonsweredrawnbetweenthedevelopmentoftelevisioninthe20thcenturyandthediffusionofprintinginthe15thand1
PsychologistGeorgeSpilichandcolleaguesatWashingtonCollegeinChestertown,Maryland,decidedtofindoutwhether,asmany
Englishremainsadominantanduniversallanguage,whichpresently【51】asaconnection-linkbetweengreatvarietiesofdif
Mostofustellonetwoliesaday,accordingtoscientistswhostudythesethings.Andwerarelygetcaught,becausetheliesw
(浙江大学2010年试题)ThecharacterofEuropeaneducationdemandsthatthestudentdevelop【1】andsocialindividuality.TheAmerican
Ithasbeenproposedbymanylinguiststhathumanlanguage______,ourbiologicallyprogrammedabilitytouselanguage,isstill
这次到台湾访问交流,虽然行色匆匆,但是,看了不少地方,访了旧友,交了新知,大家走到一起,谈论的一个重要话题就是中华民族在21世纪的强盛。虽然祖国大陆、台湾的青年生活在不同的社会环境中,有着各自不同的生活经历,但大家的内心都深深铭刻着中华文化优秀传统的印记,
DoingaPhDiscertainlynotforeverybody,andIdonotrecommenditformostpeople.However,IamreallygladIgotmyPhDra
A、uprightB、tightC、fastD、stiffA四个选项的意思是:A项upright“笔直的,直立的”;B项tight“紧紧的”;C项fast“快速的”;D项stiff“坚硬的,呆板的”。可以根据常识判断,此句话的意思是:中国的红木家具
美国人希望美国的压力会迫使日本消除它的贸易障碍,这些希望几乎注定会化为失望的泡影。事实上,华盛顿所面临的障碍比东京政府办公室里的几位权力经纪人还要难以对付。它必须与许多世纪以来所形成的根深蒂固的日本风俗对抗。要想使日本政府改变主意,华盛顿必须让全体日本人改
随机试题
Windows7中,默认打印机的图标左下角有一个“√”标志。
Americanssufferfromanoverdoseofwork.Regardless【C1】______whotheyareorwhattheydo,Americansspend【C2】______timeatwo
妊娠图中最主要的曲线为()
新生儿和早产儿长期吸氧可造成氧中毒肺损害,哪一种肺损害是不可逆的
从投资费用的角度看,在投资活动中所支付的全部费用形成了固定资产和无形资产。( )
检查项目档案时,抽查档案的数量不得少于()卷。
张某为甲公司的高级管理人员,掌握了公司大量的商业秘密。2016年8月,在劳动合同尚未到期时,张某被同行业乙公司高薪挖走,并开始在乙公司工作,从而给甲公司造成了巨大的经济损失。针对此案例,下列说法中不符合《中华人民共和国劳动合同法》规定的是()。
“垂直领导”与党委领导之间的关系是()。
塞尔曼提出儿童友谊发展有几个阶段?
Takingyourdogonvacationmayhavebeen【B1】______adecadeago,buttodayit’sfree.【B2】______thepet-friendlyhotel,wh
最新回复
(
0
)