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
2023-09-14
58
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/3014339.html
相关试题推荐
[originaltext]WilliamShakespearewaschristenedinthemarkettownofStrat
[originaltext]WilliamShakespearewaschristenedinthemarkettownofStrat
[originaltext]Theworldisnotonlyhungry;itisalsothirstyforwater.Th
[originaltext]Theworldisnotonlyhungry;itisalsothirstyforwater.Th
[originaltext]M:Hello,Ann.Ihaven’tseenyouinawhile.Whatseemstobeth
[originaltext]M:Hello,Ann.Ihaven’tseenyouinawhile.Whatseemstobeth
[originaltext]M:Hello,Ann.Ihaven’tseenyouinawhile.Whatseemstobeth
[originaltext]Weknowthenthatinthe,US,it’sthejobofCongresstoprop
[originaltext]Weknowthenthatinthe,US,it’sthejobofCongresstoprop
[originaltext]Weknowthenthatinthe,US,it’sthejobofCongresstoprop
随机试题
To:DavidWallaceFrom:BarbaraSmallwoodDate:Monday,June10th20--08:42:1
Pleasewriteoutthewordwiththegivenletters.[img]2014m4s/ct_eyyjsdz2012j_ey
Heissoproudthathealwaysconsidershimself____________(优越于)everyoneelse.su
A.绝对收敛 B.条件收敛 C.等比级数收敛 D.发散
按照《证券公司私募投资基金子公司管理规范》的规定,证券公司设立私募基金子公司,公
A. B. C. D.
银行为VIP客户提供比办理一般人民币业务客户更加便捷的服务,违反了“公平对待”原
某金店为增值税一般纳税人。2019年4月采取以旧换新方式零售金银首饰,向顾
主要依靠资本、劳动等生产要素投入来增加社会产品数量、推动经济增长的方式属于()
水泥混合料铺筑前,应对()等设施项目进行检查。A.基层的高程 B.模板的支设
最新回复
(
0
)