首页
登录
职称英语
[originaltext] Men have always wanted to fly like birds.(22)Birds can fly ea
[originaltext] Men have always wanted to fly like birds.(22)Birds can fly ea
游客
2024-02-11
14
管理
问题
Men have always wanted to fly like birds.(22)Birds can fly easily because they are light, but men’s bodies are heavier.
Men first went up into the air in balloons. These are big bags, and they are filled with gas.(23)Hydrogen is a useful gas for balloons. It is lighter than air. So balloons are usually filled with hydrogen.
Balloons have to fly with the wind, as they have no engines to drive them against it. Later, men made airships. These were balloons with engines, but they were not round.(24)They were long, and the engines were at the back. They were also filled with hydrogen and some of them caught fire, because the hydrogen escaped and the engines heated it. Then the airship was completely burnt in a few seconds. People go across the world by aircraft which have engines similar to but more powerful than those of cars. There is another kind of engine which we call the jet engine. An English engineer invented the jet engine. In May 1941 his new engine was fixed in an aircraft, and the aircraft flew quite well. Jet engines are very powerful. Usually two, three or four are enough for an aeroplane; but some big aircraft have six. Anyone in a moving jet plane can feel the power of the engines.(25)Jet planes can travel faster than sound. As a flying jet plane leaves its noise behind, we do not hear it until it has gone.
选项
A、They burn hydrogen to drive them.
B、They use engines to drive them.
C、They are full of natural gas.
D、They are filled with hydrogen.
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3440570.html
相关试题推荐
[originaltext]NewEnglandisanareaofmountains,valleys,andrivers.It
[originaltext]NewEnglandisanareaofmountains,valleys,andrivers.It
[originaltext]Throughouthistorymanhaschangedhisphysicalenvironmenti
[originaltext]Throughouthistorymanhaschangedhisphysicalenvironmenti
[originaltext]M:Ihavesomegoodnewsforyou.(19)I’vedecidedtosendyout
[originaltext]M:Ihavesomegoodnewsforyou.(19)I’vedecidedtosendyout
[originaltext]M:Ihavesomegoodnewsforyou.(19)I’vedecidedtosendyout
[originaltext]M:Couldyoudescribethetwopeoplewhorobbedthebank?W:Well
[originaltext]M:Couldyoudescribethetwopeoplewhorobbedthebank?W:Well
[originaltext]M:Couldyoudescribethetwopeoplewhorobbedthebank?W:Well
随机试题
TheCurieshadhopedthattheNobelPrizewouldfinallybringtheopportuni
机电设备采购分标时不需要考虑的因素为()。A.招标项目的规模 B.工程进度与
一位老年动脉硬化患者,当出现偏瘫时,不能鉴别脑溢血和脑血栓形成的是A.有无意识障
双代号网络图中工作之间相互制约或相互依赖的关系称为逻辑关系,它包括()。A、
工业统计中经营地与行政登记住所不在同一县级行政区域的统计单位,原则上归入经营地所
有研究者对幼儿园园长、教师做了一个调查,调查题目是“要全面真实地了解你园的保教质
下列关于新型城镇化背景下城市空间设计方法的表述,正确的有()。A.空间设计
下列方法中,用于排水管道更新的是( )。A、缠绕法 B、内衬法 C、爆管
患儿,4个月,生后牛乳喂养。突发四肢抽搐,面肌颤动,两眼上翻,持续数秒至数分钟后
保管期满的会计凭证,可按规定程序销毁。()
最新回复
(
0
)