首页
登录
职称英语
Someday, in【C1】______ the outer planets of our solar system, humankind wil
Someday, in【C1】______ the outer planets of our solar system, humankind wil
游客
2023-08-30
10
管理
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. [br] 【C7】
选项
A、as
B、that
C、what
D、which
答案
A
解析
结构衔接题。本处意思是:正如我们知道的那样,液态水是生命的基本需要。as引导非限定性定语从句,意思是“正如,像”,故选A项。
转载请注明原文地址:https://tihaiku.com/zcyy/2969324.html
相关试题推荐
Itisnotthe"somedayIwillwinthelottery"kindofdaydream,butthekin
Itisnotthe"somedayIwillwinthelottery"kindofdaydream,butthekin
Itisnotthe"somedayIwillwinthelottery"kindofdaydream,butthekin
Itisnotthe"somedayIwillwinthelottery"kindofdaydream,butthekin
Itisnotthe"somedayIwillwinthelottery"kindofdaydream,butthekin
Itisnotthe"somedayIwillwinthelottery"kindofdaydream,butthekin
Itisnotthe"somedayIwillwinthelottery"kindofdaydream,butthekin
Itisnotthe"somedayIwillwinthelottery"kindofdaydream,butthekin
Itisnotthe"somedayIwillwinthelottery"kindofdaydream,butthekin
Itisnotthe"somedayIwillwinthelottery"kindofdaydream,butthekin
随机试题
[originaltext]W:WillyoupleasereturnthesebookstoBobwhenyouseehim?M:
下列选项中,属于P6的主要功能的有( )。A.优化、计划和管理多个工程 B.
CT机将模拟信号转换成数字信号的器件是A.探测器 B.阵列处理机 C.预放大
一4岁儿童,因高热10小时,腹泻3次,两小时前发生抽搐,急诊来院。体温40.3℃
女性,28岁,足月顺产一男婴。产后半月,产妇寒战,高热,右乳红肿热痛,局部压痛,
从所给的四个选项中,选择最合适的一个填入问号处,使之呈现一定的规律性:
饭店服务品质具有( )特点。A.品质呈现的即时性 B.品质评价的主观性 C
关于市场营销的说法,错误的是( )。A.市场营销是个人和集体通过创造、提供出售
()是指若超过规定的特性值要求,将造成产品部分功能丧失的质量特性。A:重要质量特
某混凝土工程招标清单工程量为200m3,合同约定的综合单价为600元/m3,当实
最新回复
(
0
)