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
考研
Now that we are fairly sure that there are many Earth-like planets in the Galaxy, the time is ripe (or almost so) to wonder whet
Now that we are fairly sure that there are many Earth-like planets in the Galaxy, the time is ripe (or almost so) to wonder whet
admin
2022-01-04
1
问题
Now that we are fairly sure that there are many Earth-like planets in the Galaxy, the time is ripe (or almost so) to wonder whether these new worlds do indeed have a high probability of hosting new forms of life.
Currently, the best【C1】________on the existence of other planets comes from NASA’s【C2】________Kepler satellite, which has been mapping an area of the sky【C3】________some 150,000 stars.
Scientists estimate that around 5 percent of planets in our galaxy have masses similar【C4】________Earth’s and, possibly, are within the habitable zone of their stars, meaning that【C5】________they hold water it has a high chance of being liquid.【C6】________there are about 200 billion stars in our galaxy alone, scientists estimate that there should be about 10 billion Earth-size planets. Not bad, especially if we【C7】________that to be Earth-size and within a habitable zone is all it takes for life to take hold in an【C8】________world. In practice, however, the situation is much more【C9】________, since it depends on what life is and how it appears in a planet,【C10】________on the planet’s detailed geological history.
Here on Earth life appeared some 3.5 billion years ago. 11 that it may have been here as far【C12】________as 3.8 billion years ago remain tentative. For about the first three billion years, life on earth was【C13】________in the form of single-cell creatures. Only when Earth’s atmosphere was full of oxygen did more sophisticated organisms appear.
【C14】________its unusual atmosphere, Earth’s heavy, single moon, its magnetic field also did something else that allowed complex life to【C15】________on its surface,【C16】________these, Complex life would find it very hard to【C17】________and survive.
The results from Kepler’s mission are encouraging and exciting. We have the【C18】________of confirming the existence of countless other worlds out there. Based on these findings, we should indeed【C19】________that other worlds would host some kind of simple life. However, as some scientists argued, Earth and its ability to host complex life will probably remain a【C20】________phenomenon in this and other galaxies.
【C12】
选项
A、back
B、away
C、forward
D、down
答案
A
解析
如果生命在38亿年前(3.8 billion years ago)就出现的话,也意味着它的出现时间应追溯回更遥远的古代。A项back代入as far…as的表达后。组成了一个惯用表达,意为“早在(……时间),最早至……”。B项away代入as far…as的表达为“最远至……”,指距离。C项forward代入as far…as后表示“往前至……”,语义与语篇要求相矛盾。D项down代入as far…as后意为“往下至……”,也不涉及时间。
转载请注明原文地址:https://kaotiyun.com/show/Bsi4777K
0
考研英语二
相关试题推荐
Troublewasexpectedatthefootballmatch,sothepolicehadtobethere______.
Nameshavegainedincreasingimportanceinthecompetitiveworldofhighereducation.Ascollegesstriveformarketshare,they
Officejobsareamongthepositionshardesthitbycompumation.Wordprocessorsandtypistswillloseabout93,000jobsoverthe
Wearelivinginoneofthoseperiodsinhumanhistorywhicharemarkedbyrevolutionarychangesinallofman’sideasandvalue
Thegreatrecessionmaybeover,butthiseraofhighjoblessnessisprobablybeginning.Beforeitends,itwilllikelychanget
Thesmoothlandingofshuttle(航天飞机)Discoveryendedaflightthatwassuccessfulinalmosteveryrespectbutone:thedislodging
Manyadultsmaythinkthey’regettingenoughshut-eye,butinamajorsleepstudyalmost80percentofrespondentsadmittedton
IfAmericanmedicinewereapatient,hewouldweigh350poundsandbegainingfast.Despitebeingrepeatedlycounseledaboutthe
Inthedaysbeforepreschoolacademieswereallbutmandatoryforkidsunder5,IstayedhomeandgotmyearlyeducationfromMi
InJanuarycommutersvotedBirminghamNewStreetoneofBritain’sworstrailwaystations.Eachdaynearly150,000peoplemoveth
随机试题
下列选项不属于省、自治区、直辖市人民司法行政部门在审批时应当审查的内容的是()
请简述实际成本核算的一般流程。
下列属于集体决策方法的有()。
________hisfluentEnglish,hemust________inAmericaforalongtime.
传染性单核细胞增多症的典型表现为__________、__________、__________。
为完成原型定向阶段的主要学习任务,教师应做些什么工作?
拍摄:剪辑:放映
Ithappenedtomerecently.IwastellingsomeonehowmuchIhadenjoyedreadingBarackObama’sDreamsFromMyFatherandhowit
“在阳光普照的时候,你只当它烛光闪耀;在花团锦簇的时候,你只当它小草萌发;在硕果累累的时候。你只当它流星闪过。”对于这句话,你怎么理解?
2003年12月,公民甲为买房子向公民乙借了4000元钱,约定第二年3月底以前偿还。为了保证能及时还钱,甲将自己的一辆价值4500元的摩托车交给乙作为质物,双方约定,在甲不能偿还借款时,该摩托车就归乙所有。请回答下列问题:(1)甲乙两人的质押合
最新回复
(
0
)