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
2009-01-05
35
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、people might have to migrate there someday
B、people could live there naturally
C、life has ever existed there
D、its atmosphere is quite different
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/yMBK777K
0
专业英语四级
相关试题推荐
Inmanycountries,whenpeoplegivetheirname,theyrefertothemselvesusingtheirlastnameorfamilyname.IntheUnited
HowtoBuildYourVocabularyEffectivelyVocabularyisthefoundationoflearningalanguage.Withoutit,noneoftheski
HowtoBuildYourVocabularyEffectivelyVocabularyisthefoundationoflearningalanguage.Withoutit,noneoftheski
Changesinthetechnologyofcommunicationareoccurringsorapidlythatwehumanbeingsnowmovethroughacloudofmessagesa
DavidCameronhasnoticedthathealthandsafetyregulationsstopschoolstakingchildrenoutonfieldtrips,outdooractivitie
Congestedcitiesarefastbecomingtesttubesforscientistsstudyingtheimpactoftrafficfumesonthebrain.Asroadwayscho
Followingareagraphshowingthewaterconsumptionindifferentregionsin2000andpredictingincreasein2050,andanexcerpt
(1)WhenMaggiewasgonetosleep,Stephen,wearytoowithhisunaccustomedamountofrowingandwiththeintenseinwardlifeof
ThecauseofmostofthedivorcecasesintheU.S.is
随机试题
1982年宪法规定中华人民共和国中央军事委员会领导全国武装力量,它从属于国家最高()
药品生产、经营企业的经营行为符合规定的是
房地产经纪机构财务管理的内容主要包括()。[2010年考试真题]
对某投资项目进行敏感性分析,采用的评价指标为内部收益率,基准收益率为15%,基本方案的内部收益率为18%,对于不确定性因素销售收入,当销售收入降低10%,内部收益率为15%时,销售收入变化的临界点为:
化学教师的板书应该科学规范,下列化学名词书写正确的是()。
_________,家书抵万金。(唐.杜甫《春望》)
若f(—x)=—f(x),且在(0,+∞)内f’(x)>0,f"(x)>0,则在(一∞,0)内().
Accordingtothepassage,mostpeoplesaidtheydidn’tlikeinstantcoffeebecause______.Howmanyitemswereincludedineach
A、Theyarelessexpensivethanothers.B、Theyareworththemoneytheycost.C、Theyarebetterfortheeyesthanothers.D、They
MobilephonesWhatAreMobilePhones?Amobilephone,alsoknownasacellphoneorcellularphone,isaportableelectronic
最新回复
(
0
)