首页
登录
职称英语
[originaltext] The great advance in rocket theory 40 years ago showed that l
[originaltext] The great advance in rocket theory 40 years ago showed that l
游客
2024-06-12
2
管理
问题
The great advance in rocket theory 40 years ago showed that liquid-fuel rockets were far superior in every respect to the skyrocket with its weak solid fuel, the only kind of rocket then known. However, during the last decade, large solid-fuel rockets with solid fuels about as powerful as liquid fuels have made their appearance, and it is a favorite layman’s question to inquire which one is "better". The question is meaningless; one might as well as ask whether a gasoline or a diesel engine is "better". It all depends on the purpose. A liquid-fuel rocket is complicated, but has the advantage that it can be controlled beautifully. The burning of the rocket engine can be stopped completely; it can be reignited when desired. A solid-fuel rocket, on the other hand, is rather simple in construction, though hard, to build when a really large size is desired. But once you have a solid-fuel rocket, it is ready for action at a very short notice. A liquid-fuel rocket has to be fueled first and can not be held in readiness if or very long after it has been fueled. However, once a solid-fuel rocket has been ignited, it will keep burning. It can’t be stopped and reignited whenever desired. Because a solid-fuel rocket can be kept ready for a long time, most military missiles employ solid fuels, but manned space flight needs the fine adjustments that can only be provided by liquid-fuel rocket. It may be added that a liquid-fuel rocket is an expensive device; a large solid-fund rocket is, by comparison, cheap.
选项
A、The fuel is cheap.
B、They can be stopped and reignite.
C、They are cheap to build.
D、They must be used soon after fueling.
答案
C
解析
Which of the following statements is NOT the characteristic of liquid-fuel rockets?文中最后一句话“a liquid-fuel rocket is an expensive device.”故选C。
转载请注明原文地址:https://tihaiku.com/zcyy/3630605.html
相关试题推荐
[originaltext]W:Hello,listeners!Welcometoourprogram.Ourtoday’sguestis
[originaltext]W:Hello,listeners!Welcometoourprogram.Ourtoday’sguestis
[originaltext]M:Oh,Jane,you’reearly!I’mhappyyou’rehereearlytodaybeca
[originaltext]M:Oh,Jane,you’reearly!I’mhappyyou’rehereearlytodaybeca
[originaltext]BelfastistheCapitalofNorthernIslandandamajorcityin
[originaltext]Yourprofessorhasaskedmetotalktoyoutodayabouttheto
[originaltext]Inthe18thcenturyFrencheconomistsprotestedtheexcessive
[originaltext]Inthe18thcenturyFrencheconomistsprotestedtheexcessive
[originaltext]W:Wenowinterruptourregularschedulednewsprogramtobringy
[originaltext]W:Wenowinterruptourregularschedulednewsprogramtobringy
随机试题
[originaltext]W:Webroughtinapersontohelpusunderstandwhatregretsare
Oneofthebiggestvariableswhenflying,isthecompanythatyou’reforced
发包人有下列()情形,工程所在地建设行政主管部门可以限制其承揽新的工程或者新的
经纪人在洽谈签约艺人的戏剧演出活动,一般情况下效益都是点中首要考量的是()A.导
关于桩侧负摩阻力和中性点的描述,下列()是不正确的。 A.中性点处,既无正摩
(2017年真题)()认为个人理财是在分析个人和财务现状、能力的基础上,作
葶苈子与桑白皮的共同功效有A.降气化痰 B.泻肺平喘 C.清肠疗痔 D.润
(2017年真题)人力资源管理发展的顺序是()。A.人事管理萌芽阶段→科学管理
(2021年真题)关于工程项目经济评价中财务分析和经济分析区别的说法,正确的有(
小儿腹泻时口服补盐液的电解质张力是( )。A.1/4张 B.1/3张 C.
最新回复
(
0
)