首页
登录
职称英语
[originaltext] Science fiction writers have often imagined human beings going
[originaltext] Science fiction writers have often imagined human beings going
游客
2023-09-14
37
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、It influences the surface temperature of Mars.
B、It protects living beings from harmful rays.
C、It keeps a planet from overheating.
D、It is the main component of the air people breathe.
答案
D
解析
Why do scientists want to find out whether there is sufficient nitrogen on Mars?
文中的they(指scientists)will have to discover how much nitrogen it possesses,since nitrogen is four fifths of the air we breathe表明,科学家之所以研究火星上是否有足够的氮气是因为氮气是我们所呼吸的空气的主要成分,故D项正确。
转载请注明原文地址:https://tihaiku.com/zcyy/3014667.html
相关试题推荐
[originaltext]AlbertSchweitzerwasbornin1875inAlsace.Atthattime,i
[originaltext]AlbertSchweitzerwasbornin1875inAlsace.Atthattime,i
[originaltext]AlbertSchweitzerwasbornin1875inAlsace.Atthattime,i
[originaltext]AlbertSchweitzerwasbornin1875inAlsace.Atthattime,i
[originaltext]Undernormalconditionstheactofcommunicationrequiresthe
[originaltext]BillGates,theheadoftheworld’sbiggestcomputersoftware
[originaltext]GeneralizingabouteducationintheUnitedStatesinvolvesso
[originaltext]GeneralizingabouteducationintheUnitedStatesinvolvesso
[originaltext]Yourprofessorhasaskedmetotalktoyoutodayabouttheto
[originaltext]Yourprofessorhasaskedmetotalktoyoutodayabouttheto
随机试题
Untilaround1930fewUnitedStatesCivilWarhistorianspaidmuchattention
TheStructureoftheCanadianGovernmentI.IntroductionA.Can
Here’saquestionaboutchickensandeggsyoumaynothaveheardbefore:How
材料题 通读正面的短文,掌握其大意。然后,从每小题的四个选择项中选出可填入相应
A. B. C. D.
(2013年)下列关于城镇土地使用税征收管理的说法,正确的有( )。A.城镇土地
共用题干 某新建商业用房的完全成本为2500元/m2,开发商希望的目标利润率是
从所给四个选项中,选择最合适的一个填入问号处,使之呈现一定的规律性: A.如上
企业内部的业务不包括()。A.改革过程 B.革新过程 C.营运过程 D.售
人力资源之所以能够成为一种异质性资源,是因为它具备了()等方而的特征A.价值性
最新回复
(
0
)