首页
登录
职称英语
[originaltext] Science fiction writers have often imagined human beings goin
[originaltext] Science fiction writers have often imagined human beings goin
游客
2023-09-17
53
管理
问题
Science fiction writers have often imagined human beings going to live on Mars. But these days, scientists are taking the idea seriously. It has a great deal to recommend it, since it might solve the problem of overcrowding on the earth. But obviously, it would not be worth making the effort unless people could live there naturally. If the atmosphere were like that of the earth, this might be possible. But in fact it is mostly carbon dioxide. Apart from that, there are other problems to be overcome. For example, the temperature would have to be raised from 60 degrees below zero to 15 degrees above it. Scientists who study Mars have laid down the program that they can follow. To begin with, they will have to find out whether life has ever existed on the planet of Mars in the past. Secondly, they will have to make a reliable map of its surface. And finally, they will have to make a list of the gases. Above all, they will have to discover how much nitrogen it possesses, since nitrogen is four fifths of the air we breathe. They are surprisingly optimistic about raising the temperature on Mars and believe it could be done in two hundred years. It will take a bit longer, though, to transform the atmosphere so that human beings, could live there. Scientists estimate that this will take one hundred thousand years.
选项
A、Its chemical elements must be studied.
B、Its temperature must be lowered.
C、Big spaceships must be built.
D、Its atmosphere must be changed.
答案
D
解析
What is one of the things that must be done before man can live on Mars?
转载请注明原文地址:http://tihaiku.com/zcyy/3022671.html
相关试题推荐
[originaltext]W:Hello,AirChina.WhatcanIdoforyou,Sir?M:CanIbooka
[originaltext]M:I’dliketoseeyourmanager.W:Sorry,hewon’tbebackfrom
[originaltext]M:I’dliketoseeyourmanager.W:Sorry,hewon’tbebackfrom
[originaltext]M:I’dliketoseeyourmanager.W:Sorry,hewon’tbebackfrom
[originaltext]W:Whereareyougoingforyourholidays,Charles?M:ToAustrali
[originaltext]W:Whereareyougoingforyourholidays,Charles?M:ToAustrali
[originaltext]W:Whereareyougoingforyourholidays,Charles?M:ToAustrali
[originaltext]M:Helen,canIhavealookatyournewspaper?W:Sure,goahead.
[originaltext]W:Ourbedroomneedscleaning.Shallwecleanitnow?M:Thanky
[originaltext]W:Ourbedroomneedscleaning.Shallwecleanitnow?M:Thanky
随机试题
•Readthesalaryoffernegotiation.•Inmostofthelines34-45,thereisone
ThisnotonlyconstitutesaseriousthreattoChina’ssecurityandanobstaclet
GeneralIdeasaboutRhetoricI.Thedefinition&unders
Somepeoplemayovereatbecausethey’reunabletotasteand【B1】______thefat
Toronto’sthirdCityHall,nowknownasOldCityHall,wasdesignedbyEdwar
计算低温热水地板辐射采暖热负荷时,下列哪一项是错误的?A.按正常热负荷乘以0.9
乳牙何时出齐A.3.5岁 B.2.5岁 C.1~2岁 D.1.5岁 E.
下列选项中不属于现代学制的主要类型的是( )A.双轨学制 B.单轨学制 C.
关于各复利系数之间关系的说法中,正确的有( )。A.等额序列支付现值系数与等额序
张某是某地区的公务员,冒用表哥李某的名义出资并将其作为股东在公司登记机关登记,但
最新回复
(
0
)