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
Scientists are interested in Mars because ______.
Scientists are interested in Mars because ______.
admin
2010-02-17
79
问题
Scientists are interested in Mars because ______.
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’s mostly carbon dioxide. Apart from that, there are other problems to be overcome. For example, the temperature would have to be raised from 60 below zero to 15 above it. Scientists who study Mars have let out the programme that they can follow. To begin with, they will have to find out whether life has ever existed on the planet 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 200 years. It would take a bit longer, though, to transform the atmosphere so that human beings could live there. Scientists estimate that this will take 100,000 years.
选项
A、can raise the temperature of Mars
B、can protect living beings from harmful rays
C、can change the atmosphere of Mars
D、is an important part of the air people breathe
答案
D
解析
转载请注明原文地址:https://kaotiyun.com/show/MynK777K
0
专业英语四级
相关试题推荐
ShortStoryI.Threeformsoffiction—shortstory,novella,andnovel.II.【T1】___________oftheshortstory:A.Setting-
EthicsinCompaniesI.TheimportanceofethicsA.【T1】______enablescompaniestoexploittheeconomicadvantages,whereas【T2】_
TheMessagesinDistanceI.Peoplefromdifferentcultures【T1】________differentlyA.NorthAmericansstandabouttwofeetapa
TheMessagesinDistanceI.Peoplefromdifferentcultures【T1】________differentlyA.NorthAmericansstandabouttwofeetapa
PassageOneBullyingcanhaveharmfuleffectsonchildhooddevelopment,andthelatestresearchrevealsthosedetrimentalin
Onceuponatime,peoplewholivedalonetendedtobethoseoneithersideofmarriage—twenty-somethingprofessionalsorwidowe
Earlyanthropologists,followingthetheorythatwordsdeterminethought,believedthatlanguageanditsstructurewereentirel
Morethanfortythousandreaderstolduswhattheylookedforinclosefriendships,whatthe 【C1】______friends,whattheywere
BlackdeaththatdroveNewtonfromhiscollegeandintoamomentousdiscovery,【C1】______Englandin1665.Astronomicalrecords
Canelectricitycausecancer?Inasocietythatliterallyrunsonelectricpower,theveryideaseemspreposterous.Butformore
随机试题
房劳过度,易损伤的脏腑是()
病理性Q波见于哪些疾病
患者,女,30岁,病毒性感冒,护士对其进行健康指导,下列不正确的是
五行中具有“曲直”特性的是木。()
关于安全生产地方性法规的法律效力,下列说法中,正确的是()。
证券组合管理的意义在于采用适当的方法选择多种证券作为投资对象,以达到在保证预定收益的前提下使投资风险最小或在控制风险的前提下使投资收益最大化的目标。()
银行本票的提示付款期限最长不得超过()。
直观行动思维活动的典型方式是()。
()是教育立法程序的最后一个环节,也是必须经过的一个环节。
Oneofthebestwaysforpeopletokeepfitisto________healthyeatinghabits.
最新回复
(
0
)