首页
登录
职称英语
The great advance【C1】______rocket theory 40 years ago showed that liquid-fue
The great advance【C1】______rocket theory 40 years ago showed that liquid-fue
游客
2023-12-27
9
管理
问题
The great advance【C1】______rocket theory 40 years ago showed that liquid-fuel rockets were far【C2】______in every respect to the skyrocket with its weak solid fuel, the only kind of rocket then known.【C3】______, during the last decade, large solid-fuel rockets with【C4】______fuels about as powerful as liquid fuels have【C5】______their appearance, and it is a favorite layperson’s question to【C6】______which one is "better". The question is meaningless.【C7】______might as well ask whether a gasoline or a diesel engine is "better". It all【C8】______on the purpose. A liquid-fuel rocket is complicated,【C9】______has the advantage that it can be controlled beautifully. The burning of the rocket engine can be stopped completely; it can be reignited when【C10】______.【C11】______, the thrust can be made to vary by adjusting the speed of the fuel pumps. A solid-fuel rocket, on the other hand, is rather【C12】______in construction,【C13】______hard to build when a really【C14】______size is desired. But once you have a solid-fuel rocket, it is ready for action【C15】______very short notice. A liquid-fuel rocket has to be fueled first and cannot be【C16】______readiness for very long after it has been fueled.【C17】______, once a solid-fuel rocket has been ignited, it will keep burning. It cannot be stopped and reignited【C18】______desired(it could conceivably be stopped and reignited after a pre-calculated time of burning has e-lapsed. and its thrust cannot be varied. Because a solid-fuel rocket can be kept ready for a long time, most military missiles【C19】______solid fuels, but human-piloted spaceflight needs the fine adjustments that can【C20】______be provided by liquid fuels. [br] 【C17】
选项
A、On the contrary
B、Meanwhile
C、Rather
D、However
答案
D
解析
此处句意转折。
转载请注明原文地址:https://www.tihaiku.com/zcyy/3308730.html
相关试题推荐
Withtheadvancementofscience,scientistsareabletofindoutthepathsofst
EversincetheeconomistDavidRicardoofferedthebasictheoryin1817,eco
Thetheoryofevolutionbynaturalselectionwasputforwardinthe1850sind
Thetheoryofevolutionbynaturalselectionwasputforwardinthe1850sin
EversincetheeconomistDavidRicardoofferedthebasictheoryin1817,eco
Hewaslookingimpatientatthevisitingsalesman,whoshowednosignsofgettin
Freudiantheoryindeedtookwestern20th-centurycivilizationbystorm.How
Freudiantheoryindeedtookwestern20th-centurycivilizationbystorm.How
Freudiantheoryindeedtookwestern20th-centurycivilizationbystorm.How
Freudiantheoryindeedtookwestern20th-centurycivilizationbystorm.How
随机试题
Thisbookisabouthowthesebasicbeliefsandvaluesaffectimportantsidesof
Heisoneofthemostfamous______(surgery)inthishospital.surgeons词性转换。在形容词
Somanyofusholdontolittleresentmentsthatmayhavestemmedfromanar
关于抗震设计的底部框架-抗震墙砌体房屋结构的说法,正确的是( )。A.抗震设防
某机械设计公司为了规范内部设计图纸的存储标准,提高文件的安全性和工作效率,决定新
本题主要考查无理数的表示方法。 既约分数的定义:分子、分母只有公因数1的分数,或者分子和分母互质的分数,叫做最简分数,又称既约分数。将循环小数化成分数的关
诊断急性出血性胰腺炎比较好的指标是A.血清弹性蛋白酶 B.血、尿淀粉酶 C.
2020年北京市生态与环境价值中,年值同比增长慢于贴现值的指标有:A.4
对于居住物业,( )是房地产资产管理的全部内容。A.物业管理 B.设施管理
年平均日交通量为15000~30000辆(四车道),为连接重要政治、经济中心的公
最新回复
(
0
)