首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Rockets in the Sky If someone asked you, "What color is the sky?" I expect that you would answer, "Blue. " I am afraid that
Rockets in the Sky If someone asked you, "What color is the sky?" I expect that you would answer, "Blue. " I am afraid that
admin
2014-03-13
39
问题
Rockets in the Sky
If someone asked you, "What color is the sky?" I expect that you would answer, "Blue. " I am afraid that you would be wrong. The sky has no color. When we see blue, we are looking at blue sunlight. The sunlight is shining on little bits of dust in the air.
We know that there is air all around the world. We could not breathe without air. Airplanes could not fly without air. They need air to lift their wings. Airplanes cannot fly very high because as they go higher the air gets thinner. If we go far enough away from the earth, we find there is no air.
What is the sky? The sky is space. In this space there is nothing except the sun, the moon and all the stars.
Scientists have always wanted to know more about the other worlds in the space. They have looked at them through telescopes and in this way they have found out a great deal. The moon is about 384, 000 kilometers away from the earth. An airplane cann’ t fly to the moon but there is a thing that can fly even when there is no air. This is rocket.
I am sure that you are asking, "How does a rocket fly?" If you want to know, get a balloon and then blow it up until it is quite big. Do not tie up the neck of the balloon. Let go! The balloon will fly off through the air very quickly. The air inside the balloon tries to get out. It rushes out through the neck of the balloon and this pushes the balloon through the air. It does not need wings like an airplane.
This is how a rocket works. It is not made of rubber(橡胶)like a balloon, of course. It is made of metal. The metal must not be heavy but it must be very strong. There is gas inside the rocket which is made very hot. When it rushes out of the end of the rocket, the rocket is pushed up into the air.
Rockets can fly far out into space. Rockets with men inside them have already reached the moon. Several rockets, without men inside them, have been sent to other worlds much farther away. One day rockets may be able to go anywhere in the space.
A rocket can fly to the moon because______.
选项
A、it looks like a balloon
B、it is much lighter than an airplane
C、it doesn’ t have wings
D、it works like an untied balloon
答案
D
解析
根据第五段可知,火箭飞行的原理与没扎口的膨胀的气球相似。
转载请注明原文地址:https://kaotiyun.com/show/roGd777K
本试题收录于:
职称英语理工类A级题库职称英语分类
0
职称英语理工类A级
职称英语
相关试题推荐
DriedFoodsCenturiesago,mandiscoveredthatremovingmoisture(51)foodhelpedtopreserveit,andthattheeasiestwaytodot
DriedFoodsCenturiesago,mandiscoveredthatremovingmoisture(51)foodhelpedtopreserveit,andthattheeasiestwaytodot
ASignificanceofTestingTechniquesforSamplingMicrobesintheDeepleeSheetBSpecialFeaturesofLakeVidaCLaterExpe
AKripke’sResearchToo1BDangersofHabitualShortagesofSleepCCriticismonKripke’sReportDAWayofOvercomingInsom
Medicinedependsonotherfieldsforbasicinformation,particularlysomeoftheirspecializedbranches.
WhichofthefollowingisNOTtrueoftheJapanese?WhichofthefollowingisNOTtrueofBritain?
AAShortHistoryofNamingHurricanesBHarnessingtheHurricaneEnergyCDifficultyinForecastingtheCourseofaHurric
A.GoodresultsB.AnancientskillC.GainingattentionD.MemorytricksE.AlectureonmemorytechniquesF.Waystoimpr
Itisnecessarythatthemembershipapplicationsshouldbedispatchedimmediately.
随机试题
HowtoTametheAngerMonsterThreefactorscausingangertime—atwork:—longerworkinghoursand【L1】________
患者,男,60岁。20年前曾患肝炎。近2个月来纳差、消瘦,肝区疼痛明显。体检:轻度黄疸,面部有蜘蛛痣、腹膨隆,肝肋下2cm、剑下4cm,质硬,压痛;脾肋下3cm;移动性浊音阳性。拟诊为肝癌。现首先应检测的是
治疗心胆气虚型失眠的主方为
慢性心功能不全最常见的诱因是()
一般情况下,国内借款应按()的顺序归还。
既考虑负债带来税收抵免收益,又考虑负债带来各种风险和额外费用,并对它们进行适当平衡来稳定企业价值的是( )。
设某地区某时流通中的通货为1500亿元,中央银行的法定存款准备金率为7%,商业银行的存款准备金为500亿元,存款货币总量为4000亿元。根据以上材料,回答下列问题:中央银行投放基础货币的途径有()。
[资料一]甲公司属于商品流通企业,为增值税一般纳税人,适用增值税税率为17%,商品售价中不含增值税。该公司只经营乙类商品并采用毛利率法对发出商品计价,季度内各月份的毛利率根据上季度实际毛利率确定。2013年度发生如下与商品销售和职工薪酬有关的事项
下列关于个人所得税的表述中,正确的有()。
A、OnFebruary17.B、OnFebruary7.C、OnJanuary17.D、OnJanuary7.B
最新回复
(
0
)