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
17
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、Neither of the two types of rockets is very economical.
B、The liquid-fuel rocket is best.
C、Each type of rocket has certain advantages.
D、The solid-fuel rocket is best.
答案
C
解析
What conclusion can we draw from the passage?文中提到两种火箭的优劣时,说“The question is meaningless.It all depends on the purpose.”显然两种火箭都有其长处。故选C。
转载请注明原文地址:https://tihaiku.com/zcyy/3630602.html
相关试题推荐
[originaltext]Asaresultofrisinguniversitycosts,manystudentsarefin
[originaltext]Asaresultofrisinguniversitycosts,manystudentsarefin
[originaltext]Iwillletyouknowthatthere’sabigdifferencebetweenund
[originaltext]Iwillletyouknowthatthere’sabigdifferencebetweenund
[originaltext]W:Hi,Jack.M:Hi,Jean.Iwasjustlookingforyou.W:What’su
[originaltext]W:Hi,Jack.M:Hi,Jean.Iwasjustlookingforyou.W:What’su
[originaltext]W:Hi,Jack.M:Hi,Jean.Iwasjustlookingforyou.W:What’su
[originaltext]M:Excusememadam.Wouldyoumindlettingmetakealookinyour
[originaltext]M:Excusememadam.Wouldyoumindlettingmetakealookinyour
[originaltext]Anyonewhospendsatleastonesemesterincollegenoticest
随机试题
说明:以北京大学法学院院长张守文的名义,邀请Mr.Green来校做一个有关法律的讲座。内容:1.得知Mr.Green在华访
Accidentswascaused;theydon’tjusthappen.Thereasonmaybeeasytosee:
Nowthatyoucankeepyourmindopentonewwaysofthinking,insteadofturning
Youmightthinkalittleglobalwarmingisgoodforfarming.Longer,warmer
具有断点续传功能的FTP客户端软件,在续传时需要与FTP服务器交换断点的位置信息
遗精、滑精和早泄等与气的哪项功能减退有关A.气化作用 B.固摄作用 C.防御
下列关于尼可刹米的叙述,错误的是()A.治疗呼吸肌麻痹所致的呼吸抑制效果
某工厂要扩建三栋厂房.,于是委托某勘察单位进行勘察。三栋厂房预算额分别为1号:
关于财产税所具有的优点的说法,正确的有()A.符合税收的纳税能力原则 B
城市管道巡视检查,检测手段包括()等方法及仪器设备。A.探测雷达 B.声呐
最新回复
(
0
)