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
34
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
Gotapenhandy?Tobestestimateyourstart-upcosts,you’llneedtomakea
Inrecentyearstherehasbeenmuchtalkofa"renaissance"inAmericanmanu
肝硬化患者血清免疫学检查,发现IgM显著增高,血清抗线粒体抗体强阳性,最可能的诊
酸奶中的乳酸菌进入肠道后可抑制腐败菌的生长,调整肠道菌相。( )
下列不属于医疗卫生机构职责的是:A.不得录用未取得护士执业证书的人员 B.配备
(2016年真题)不主动寻求取得超越市场的表现,而是试图复制某指数表现的基金是(
利用CAD软件生成题41图的建筑表达,主要利用了其何种功能?( ) A.交互
酶保持催化活性,必须A.酶分子完整无缺 B.有酶分子上所有化学基团存在 C.
下列乳牙龋病的预防措施中,哪一项是正确的A.不吃甜食,饭后漱口 B.每天晚上刷
根据九部委设备采购合同的规定,由于买方原因在最后一批合同设备交货后( )内未能
最新回复
(
0
)