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
2024-05-13
37
管理
问题
The great advance in rocket theory 40 years ago showed that liquid-fuel rackets 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 a bout as powerful as powerful 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 bunting of the rocket engine can be stopped completely; it can be reignited when desired. A solid-fuel rocket, tin 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 flint and Carl not be held in readiness in very long slier 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 missiles employ solid fuels, but manned space flight needs the line adjustments that can only be pro vided 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 be passage?
转载请注明原文地址:https://tihaiku.com/zcyy/3597167.html
相关试题推荐
[originaltext]Centuriesago,duringtheMiddleAges,mostofthelandinEur
[originaltext]M:Manypeopleseemtobeonadiet.Haveyounoticedthat,Anna?
[originaltext]M:Manypeopleseemtobeonadiet.Haveyounoticedthat,Anna?
[originaltext]M:Manypeopleseemtobeonadiet.Haveyounoticedthat,Anna?
[originaltext]M:MissHanson,thankyouforsendingmethisnote.I’msorryto
[originaltext]M:MissHanson,thankyouforsendingmethisnote.I’msorryto
[originaltext]M:MissHanson,thankyouforsendingmethisnote.I’msorryto
[originaltext]Thegreatadvanceinrockettheory40yearsagoshowedthatl
[originaltext]Thegreatadvanceinrockettheory40yearsagoshowedthatl
[originaltext]Thegreatadvanceinrockettheory40yearsagoshowedthatl
随机试题
Howmenfirstlearnttoinventwordsisunknown;inotherwords,theorigin
Peopledonotanalyzeeveryproblemtheymeet.Sometimestheytrytoremembe
Whichdoyouthinkis______important,healthorwealth?A、mostB、themostC、the
关于买进看跌期权的盈亏平衡点(不计交易费用),以下说法正确的是()。A、盈亏平衡点=执行价格+权利金B、盈亏平衡点=期权价格一执行价格C、盈亏平衡点
治疗产褥中暑暑伤津气证,应首选A.白虎汤 B.竹叶石膏汤 C.清暑益气汤
“肝阳上亢”属于下列概念中的A:症状B:疾病C:体征D:病因E:证候
( )是以实现劳动关系双方的沟通。但不一定达成协议为目的的企业民主管理制度。A
不属于“佐药”作用的是A.调和方中诸药作用 B.病重邪甚,可能拒药时,配用与君
根据《药品管理法》规定,下列属于药品的有A.化学原料药 B.保健品 C.疫苗
A.头孢氨苄 B.头孢克洛 C.头孢呋辛 D.硫酸头孢匹罗 E.头孢曲松
最新回复
(
0
)