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
Someday, in【C1】______ the outer planets of our solar system, humankind will want to do【C2】______ send small probes that merely
Someday, in【C1】______ the outer planets of our solar system, humankind will want to do【C2】______ send small probes that merely
admin
2013-06-02
32
问题
Someday, in【C1】______ the outer planets of our solar system, humankind will want to do【C2】______ send small probes that merely fly rapidly by them. In time, we will want【C3】______ spacecraft that will go【C4】______ orbit around these alien planets, land robots on their moons, and even return rock and soil sample back to Earth.【C5】______ , we will want to send humans to their moons, on at least【C6】______ which liquid water—the fundamental requirementfor life【C7】______ we know it—is believed to be【C8】______ .
For missions such as these, we will need rockets powered by a nuclear reaction【C9】______ igniting chemicals. Chemical rockets have served us well. But the【C10】______ low amount of energy that they can deliver for a given mass of fuel is a severe【C11】______ when dispatching spacecraft【C12】______ long distances. To reach the outer planets, for example, a chemically-powered space vehicle must【C13】______ fuel by having a very small mass and making【C14】______ use of gravity "assists", in which the craft maneuvers close enough to a planet for the planet’s gravity to propel the craft forward,【C15】______ its speed.
In technical term, chemical rockets have low【C16】______ velocity growth, which means that their exhaust velocities are not high enough to【C17】______ very high speed to the rocket. Nuclear rockets,【C18】______ their chemical counterparts, could impart a maximum velocity of【C19】______ about 22 kilometers a second. Such a high velocity would make possible a direct path to Saturn (土星), reducing travel time from about seven years to as【C20】______ as three.
【C10】
选项
A、exactly
B、extremely
C、relatively
D、conversely
答案
C
解析
副词辨义题。本处意思是:化学燃料火箭只能提供相对较低能量…。故选C relatively“比较地,相对地”。
转载请注明原文地址:https://kaotiyun.com/show/12n7777K
0
大学英语六级
相关试题推荐
Itisnotthe"somedayIwillwinthelottery"kindofdaydream,butthekindthattapsintothehidden,partofyourbrain.Tha
Itisnotthe"somedayIwillwinthelottery"kindofdaydream,butthekindthattapsintothehidden,partofyourbrain.Tha
Itisnotthe"somedayIwillwinthelottery"kindofdaydream,butthekindthattapsintothehidden,partofyourbrain.Tha
Fromthechildtooldage,wealluselanguageasameansof【B1】______ourknowledgeofourselvesandtheworldaroundus.When
TheAmericanideaofrespectinghumanrightscamefromseveralsources.First,thecolonistshadbeen【36】oftheirfightsinthe
TheAmericanideaofrespectinghumanrightscamefromseveralsources.First,thecolonistshadbeen【36】oftheirfightsinthe
A、None.B、Two.C、Three.D、Morethanthree.D原文提到对减肥的人来说要少食多餐,在三次正餐之外还要吃一些健康小点心,所以选D。
ArtificialIntelligenceI’msurethatHansMoravecisatleastassaneasIam,buthecertainlybroughttomindtheclassic
A、Indonesia.B、YellowstoneNationalPark.C、TheWales.D、TheGreatBritain.A①A提到lasteruption后听到的地点,为答案。②对于对话中提及的时间、地点、数据、顺序应该特
A、Three.B、Four.C、Five.D、Six.D细节题。本题的设题点在数字信息处。男士问女士知不知道paper都有哪些用途,女士一共说出了纸的6种用途,即纸可以用于newspapers,books,writingpaper,envelo
随机试题
工作温度为-1.6°C的管道为低温管道。()
精索由哪几部分组成
A.腹股沟斜疝B.腹股沟直疝C.股疝D.睾丸鞘膜积液E.交通性鞘膜积液老年男性,腹股沟内侧半球形肿物,压住内环肿物仍可突出,可能是
在施工合同中,不论何种形式的仲裁协议,都应包括()。
已知某工程土建基础部分分配投资限额为1000万元,工程建设年限为5年,工程造价上涨指数5%,此时的实际限额约为()万元。
根据《水利水电建设工程验收规程》SL223—2008的有关规定,合同工程完工验收应由()主持。
重力式码头胸墙混凝土,在施工缝处浇筑时,应清除已硬化混凝土表面上的()。
基金产品的风险有()。
2011年1月1日,甲公司经批准发行到期还本、分期付息的公司债券200万张。该债券每张面值为100元,期限为3年,票面年利率为5%,每年1月1日支付上一年利息,该债券实际年利率为6%。假定不考虑债券的发行费用。甲公司发行债券实际募得资金19465万元,债券
WhenIlastsawthem,thepolicehadchasedtherobbersdownColumbusStreet.
最新回复
(
0
)