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
58
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、In 200 years.
B、In 10,000 years.
C、In 100,000 years.
D、Unknown.
答案
C
解析
转载请注明原文地址:https://kaotiyun.com/show/NMBK777K
0
专业英语四级
相关试题推荐
Inmanycountries,whenpeoplegivetheirname,theyrefertothemselvesusingtheirlastnameorfamilyname.IntheUnited
LearningaboutCognitiveGrammar(CG),anapproachtotheanalysisanddescriptionoflanguagestructure,isnoteasy.One
LearningaboutCognitiveGrammar(CG),anapproachtotheanalysisanddescriptionoflanguagestructure,isnoteasy.One
Changesinthetechnologyofcommunicationareoccurringsorapidlythatwehumanbeingsnowmovethroughacloudofmessagesa
NotwomanheldapresidentialcabinetpositionintheUnitedStatesuntil1933,whenFrancesPerkinsbecamesecretaryoflabor.
Somesocialscientistshaveclaimedthatdivorceharmschildrenfortherestoftheirlivesleadingthemtoformmarriagesash
Whatpersonalqualitiesaredesirableinateacher?Probablynotwopeoplewoulddrawupapproximatelysimilarlists,butI【M1】_
Foryears,nonprofithospitalshaveshiedawayfromquantifyingtheamountofcharitablecaretheyprovidecommunities.Hospit
FollowingareagraphshowingthecurrentsituationofsmartphonepenetrationintheUKandanexcerptonthefuturetrendofsm
(1)WhenMaggiewasgonetosleep,Stephen,wearytoowithhisunaccustomedamountofrowingandwiththeintenseinwardlifeof
随机试题
A、Shelikedtodothingsonherown.B、Shewasn’tgoodatmakingfriends.C、Shewasleftoutbyherclassmates.D、Shewastoosh
患者,女,51岁。因反复胸闷、胸痛2年余就诊。2年前因琐事与人争吵后,出现左前胸胀痛,伴胸胁胀闷、心悸,休息后缓解,未予重视。此后,胸闷胸痛反复发作,多于情绪波动后症状加重,严重时可放射至左后肩。患者情志抑郁,善太息,纳差,寐欠安,小便黄,大便失调。唇舌紫
神经嵴是神经板外侧缘细胞迁移到神经管背侧形成的纵行细胞索,是周围神经系统的原基。
重大事故应急根据事故的性质、严重程度、事态发展趋势和控制能力实行分级响应机制,对不同的响应级别,相应地明确事故的通报范围,应急中心的启动程度,应急力量的出动,设备、物资的调集规模,疏散的范围,应急总指挥的职位等,下列关于事故应急响应机制的说法中,错误的是(
人的实际能力又可分为()。
通过光谱研究,我们能够发现几亿光年以外的微量元素。观测范围已经很庞大了。因此,在我们可以观测的范围里,应该具备宇宙中最普遍的环境。在这种环境中应该产生宇宙中最普遍的物质。当然,宇宙中肯定还存在一些特殊的环境和物质,但是这种环境一定不是普遍的,一定是非常稀有
互联网上每一个网络或每一台主机所分配的逻辑地址称为IP地址。目前,IP地址主要有IPv4地址和IPv6地址两大类别。下列对应错误的是:
温柔:内向:忧郁
有如下SQL语句CREATEVIEWkh-viewASSELECT姓名AS客户姓名,账户金额FROMkh执行该语句后产生的视图含有的字段名是()。
Televisionmakesusbetter______thaneverbefore.
最新回复
(
0
)