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
25
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
Whenwewantto(56)otherpeoplewhatwethink,wecandoitnotonlywith
[img]2015m7x/ct_egreqj_egreqtbz1_0100_20151[/img]Thefigureaboveshowsthepro
However,Idon’tbelievethatthereisaneedtomakeclassattendancemandatory
Studentsmustapplyforaplacebeforeattendinganyclass.Applications(申请)
下列因素中,不是容积效率影响因素的是()。A.气缸中不可避免地保留有一定的余
关于CT窗口技术,错误的是A.改变灰度 B.改变对比度 C.抑制或去除噪声
下列关于资产证券化业务的说法,正确的是( )。A.管理人未取得资产管理业务资格
基础心理学是研究()。 (A)正常成人心理现象的心理学基础学科 (B
要想达到较高的评价者信度,需要注意的问题包括()。A.测试过程要标准化
赵某因工作较忙无暇打理家务,遂与吴某口头约定,由吴某每周来赵某家两次,每次整理家
最新回复
(
0
)