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
2017-08-11
95
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.
【C20】
选项
A、rare
B、popular
C、natural
D、new
答案
A
解析
However表转折,由此应推测科学家认为在银河系或是在其他星系中.地球支撑如此复杂的生命体的能力是不同寻常的。A项rare“罕见的,特殊的”符合。
转载请注明原文地址:https://kaotiyun.com/show/5cbZ777K
0
考研英语一
相关试题推荐
"Always"."Never".TheseareprobablythetwomostpowerfulwordsintheEnglishlanguage.Evenmorepowerfulthanyesandno,s
"Always"."Never".TheseareprobablythetwomostpowerfulwordsintheEnglishlanguage.Evenmorepowerfulthanyesandno,s
Thebestsolutionistostoppretendingthatpeople’spersonalinformation,suchasSocialSecurityaccountnumbersandbirthda
Anumberofprocessesorphaseshavebeenidentifiedastypicalofcreativethinking.【F1】Inwhatlogicallywouldbethefirstph
Manyscientistsconsiderphysicsastheprototypeofascience,andindeed,physicsexhibitsanumberoffeatureswhichcanber
【F1】Waterpollutioninvolvesthereleaseintolakes,streams,rivers,andoceansofsubstancesthatbecomedissolvedorsuspende
It’seasytoscarepeopleaboutwhat’sintheirfood,butthedangerisalmostneverreal.Andthe【C1】______itselfkills.Ta
It’seasytoscarepeopleaboutwhat’sintheirfood,butthedangerisalmostneverreal.Andthe【C1】______itselfkills.Ta
It’seasytoscarepeopleaboutwhat’sintheirfood,butthedangerisalmostneverreal.Andthe【C1】______itselfkills.Ta
It’seasytoscarepeopleaboutwhat’sintheirfood,butthedangerisalmostneverreal.Andthe【C1】______itselfkills.Ta
随机试题
设f(x)在[0,+∞)上二阶可导,f(0)=0,f”(x)<0,当0<a<x<b时,有()
A.正态分布B.对数正态分布C.二项分布D.Possion分布E.χ2分布
A、含片B、口腔贴片C、舌下片D、咀嚼片E、分散片片中的药物应是易溶性的,主要起局部消炎、杀菌、收敛、止痛或局部麻醉作用
项目组织内部各组织单元之间职责与任务相互交叉的分工与衔接属于()界面。
工程进度款拨付额不超过工程价款的()。
该企业( )。陈某( )。
下列各项中,影响持有至到期投资摊余成本因素的有()。
EPQ
假设在表单设计器环境下,表单中有一个文本框且已经被选定为当前对象。现在从属性窗口中选择Value属性,然后在设置框中输入:={^2001-9-10}-{^2001-8-20}。请问以上操作后,文本框Value属性值的数据类型为()。
实体完整性约束要求关系数据库中元组的属性值不能为空。
最新回复
(
0
)