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
2023-02-14
59
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.【C11】________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.
【C16】
选项
A、Behind
B、Along
C、Over
D、Without
答案
D
解析
空格所在句的过去时态(would find)是虚拟语气的用法,意为“复杂生命体将难以生存”。空格后的these指代的是上句中的Earth’s heavy…magnetic field等复杂生命体赖以生存的条件。D项Without可表示因为缺少某个条件而引出一个虚拟的结果。A项Behind“在……之后”、B项Along“与……一起”和C项Over“在……之上”都不能表示假设的条件,用法不符合要求。
转载请注明原文地址:https://kaotiyun.com/show/ixMD777K
0
考研英语二
相关试题推荐
ManyAmericanshavebeenfeedingababyaspirinonceaday,believingitwouldprotectthemfromaheartattack,astroke,ande
ManyAmericanshavebeenfeedingababyaspirinonceaday,believingitwouldprotectthemfromaheartattack,astroke,ande
ManyAmericanshavebeenfeedingababyaspirinonceaday,believingitwouldprotectthemfromaheartattack,astroke,ande
ManyAmericanshavebeenfeedingababyaspirinonceaday,believingitwouldprotectthemfromaheartattack,astroke,ande
ManyAmericanshavebeenfeedingababyaspirinonceaday,believingitwouldprotectthemfromaheartattack,astroke,ande
Weighingyourselfregularlyisawonderfulwaytostayawareofanysignificantweightfluctuations.【C1】________,whendonetoo
Weighingyourselfregularlyisawonderfulwaytostayawareofanysignificantweightfluctuations.【C1】________,whendonetoo
Weighingyourselfregularlyisawonderfulwaytostayawareofanysignificantweightfluctuations.【C1】________,whendonetoo
Weighingyourselfregularlyisawonderfulwaytostayawareofanysignificantweightfluctuations.【C1】________,whendonetoo
Weighingyourselfregularlyisawonderfulwaytostayawareofanysignificantweightfluctuations.【C1】________,whendonetoo
随机试题
患者,男,59岁,血压140/95mmHg,他的血压属于
公司债券筹资与普通股筹资比较,则()。
根据《企业所得税法》规定,下列属于免税收入的是()。
根据规定,临时存款账户的有效期最长不得超过()年。
我国商业银行临时存款账户的有效期限最长不得超过1年。
人民群众的支持,是公安工作最大的经济优势,是做好公安工作的根本保证。()
放弃语音套餐收入,才是流量经营全面成熟的开始。可喜的是,随着4G网络的普及,技术上VoLTE已经没有问题,商业上随着用户的______,移动互联网产品的______,流量经营正在迎来井喷的时代。语音通话方式也将成为流量经营的一部分,到那时,运营商将会有更充
用不超过150字的篇幅,概括出给定资料所反映的教育公益性特征。以政府调研员的身份,用不超过400字的篇幅,归纳出在维护教育公益性的过程中,必须处理好哪几个问题。要有条理地说明,要体现针对性。
在查询设计器环境中,“查询”菜单下的“查询去向”不包括()。
Hollywoodproducedmorefilmsthananyfilmcenterintheworld.【M1】______Thewarmweathermidlonghoursofsunlight
最新回复
(
0
)