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
A、Along big rivers. B、Near the sources of rivers. C、Near the sources of lakes. D、Near the sources of fresh water. D短文中提到,历史上,人们一
A、Along big rivers. B、Near the sources of rivers. C、Near the sources of lakes. D、Near the sources of fresh water. D短文中提到,历史上,人们一
admin
2022-11-28
98
问题
Three-fourths of the world is covered with water. But only about 3% of it is fresh. All the rest is salt water, which fills the oceans and seas. In history, men have tried to build their homes near the sources of fresh water. Now, fresh water is becoming rare, but more and more is needed because of the increasing number of people. Some industries also use large amounts of fresh water in the production of steel, paper, and so on. Scientists estimate that the need of fresh water will have doubled by the year 2050. If it is the truth, we must find new ways of saving or producing it. Some nations have worked on the problem and are already sharing their information with others. They are trying to keep their rivers from being polluted. Deep wells are also being dug, and rainwater is being collected in huge artificial lakes. In one way or another, they hope to provide enough water to satisfy the needs of their people. One important way to have fresh water is to make it from seawater. In this process, the salty seawater is heated, leaving the salt. When the vapor cools down, it becomes water again. The great problem in desalting is not whether it works, but how much it costs. Building the plants is costly and so are the equipment and fuel for the process. One solution to the problem of the fresh water may be to construct companies with two purposes, that is, making fresh water and generating electricity.
16. Where did humans usually build their houses in the past?
17. How can scientists provide more fresh water for people?
18. What is the main problem in desalting water?
选项
A、Along big rivers.
B、Near the sources of rivers.
C、Near the sources of lakes.
D、Near the sources of fresh water.
答案
D
解析
短文中提到,历史上,人们一般把房屋建在能直接饮用的淡水源头附近。
转载请注明原文地址:https://kaotiyun.com/show/529D777K
0
大学英语四级
相关试题推荐
在面向对象方法中,不属于“对象”基本特点的是()。
在Access中,自动启动宏的名称是()。
在窗体中添加一个名称为Command1的命令按钮,然后编写如下事件代码:PrivateSubCommand1_Click()MsgBoxf(24,18)EndSubPublicFunctionf(mAs
Animationmeansmakingthingswhicharelifelesscomealiveandmove.Sinceearliesttimes,peoplehavealwaysbeenastonish
PeoplewhotravelalotflywithHeavenAir,becausetheyknowtheywillgetwhattheywant.Theywanttogoquicklyandsafely
Itisreportedthatbagsaregettingbiggerallthetime,andthattherearemorebagsperpersononthestreettodaythanatan
RecyclinginGaea’sGuardiansAim:protectingenvironmentthroughrecyclingTypeofgroup:
DearSir,IwillgraduatefromShanghaiUniversityofInternationalBusinessandEconomicsthisyear.Asastudentmajoring
Whatwasthesecondjobthemangot?Heworkedasa(n)_________________.
UniversalHealthCare,Worldwide,IsWithinReachA)Bymanymeasurestheworldhasneverbeeninbetterhealth.Since2000
随机试题
接入控制
社会保险基金的投资方向、投资比例()
火灾探测器中,适用于监视有易燃物质区域火灾发生的是()。
某围堰保护对象为有特殊要求的1级永久性水工建筑物,下游为一般城镇,若围堰失事,将影响工程总工期和第一台机组发电,且造成较大经济损失,围堰使用年限为2年,堰高20m,拦洪库容为0.8亿立方米,则该围堰属于()级导流建筑物。
按存款的支取方式不同,对公存款一般分为()。
下列情形中,用人单位经法定程序,可以经济性裁员的有()。
克隆技术属于生物技术中的()。
为了保证货物拼装后的安全,便于装卸作业和仓库保管,还规定一些货物不得按零担办理,如限按()办理的危险货物,需要冷藏,保温,或加温运输的货物等。
(2017·天津)循循善诱,因势利导,讲明道理,疏导思想。其中体现的德育原则是()
设α1=(1,1,1),α2=(1,2,3),α3=(1,3,t),求:(1)t为何值时,向量组α1,α2,α3线性相关;(2)t为何值时,向量组α1,α2,α3线性无关;(3)当线性相关时,将α3表为α1和α2的线性组合.
最新回复
(
0
)