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
48
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 make planes travel faster than sound.
B、They were invented by an American.
C、They are the most powerful ones.
D、They have very little noise.
答案
A
解析
转载请注明原文地址:http://tihaiku.com/zcyy/3440572.html
相关试题推荐
[originaltext]NewEnglandisanareaofmountains,valleys,andrivers.It
[originaltext]NewEnglandisanareaofmountains,valleys,andrivers.It
[originaltext]SurveysofAmericanteenagersfindthatabouthalfofthemdo
[originaltext]SurveysofAmericanteenagersfindthatabouthalfofthemdo
[originaltext]SurveysofAmericanteenagersfindthatabouthalfofthemdo
[originaltext]M:Ihavesomegoodnewsforyou.(19)I’vedecidedtosendyout
[originaltext]M:Ihavesomegoodnewsforyou.(19)I’vedecidedtosendyout
[originaltext]W:Hello!ThisisJohnsHopkins.Dr.Silver’sOffice.CanIhelp
[originaltext]W:Hello!ThisisJohnsHopkins.Dr.Silver’sOffice.CanIhelp
[originaltext]M:Couldyoudescribethetwopeoplewhorobbedthebank?W:Well
随机试题
Pleasekeepthedoor______whilethetrainismoving.A、closeB、closedC、toclose
Thereareseveralmaintypesof【B1】______andwell-knowneffectsofpollution
井巷涌水的主要来源有()。A、老窖水 B、地表水 C、地下水 D、施工用水
近年来,中央政府给西藏的财政定额补贴每年达12亿元以上,总投资46亿元的62项援
下列关于泡沫灭火装置控制阀门锈死处理原则的说法正确的是()。(A)现场检
收益性物业在运用市场法估价时,一般选取()个以上可比实例。A:2B:3C:4
钱某持盗来的身份证及伪造的空头支票,骗取某音像中心VCD光盘4000张,支票票面
美元指数中英镑所占的比重为()。A.3.6% B.4.2% C.11
银行承兑汇票的承兑银行,应当按照票面金额向出票人收取()的手续费。A:千分之一
多层砌体结构房屋的主要抗震措施有( )。A.设置钢筋混凝土构造柱 B.设置钢
最新回复
(
0
)