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 cannot 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 o f 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 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 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 fat 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. 1. Which of the following statements about a rocket is NOT true? A) It can fly when there is no air. B) It can fly without wings. C) It is made of strong metal. D) It is propelled by burning gas inside it. 2. A rocket is pushed up into the air when A) hot gas rushes out of its head. B) it is powered by gas. C) hot gas rushes out of its bottom. D) hot gas rushes out of its neck. Keys: DC
上一篇: 职称英语考试综合类阅读理解专项练习(3)
下一篇: 职称英语综合类的阅读理解练习(10)
2017届高考英语一轮复习检测:Unit1 Cultural relics (人教版必修2)Word版含答案
2017届高考英语一轮复习检测:Unit2 Healthy eating (人教版必修3)Word版含答案
2017高考英语一轮复习同步检测:M6 Unit 1《Laughter is good for you》(译林版)
2017届高考英语一轮复习检测:Unit2 Working the land (人教版必修4)Word版含答案
2017届高三英语二轮复习 动词及动词短语教案(5)
2017高考英语阅读理解一轮(暑假)训练(1)及答案
2017届高考英语一轮复习检测:Unit1 Festivals around the world (人教版必修3)Word版含答案
2017高考英语一轮复习同步检测:M8 Unit 1《The written word》(译林版)
2017届高考英语一轮复习检测:Unit4 Making the news (人教版必修5)Word版含答案
2017高考英语阅读理解一轮(暑假)训练(3)及答案
2017年高考英语一轮复习 单元总复习 新人教版必修2
2017高考英语暑假练习(5)(答案或解析)
2017高考英语暑假练习(9)(答案或解析)
2017高考英语一轮复习同步检测:M8 Unit 4《Films and film events》(译林版)
2017高考英语阅读理解一轮(暑假)训练(7)及答案
2017届高考英语一轮复习检测:Unit5 Theme parks (人教版必修4)Word版含答案
2017高考英语一轮复习同步检测:M6 Unit 2《What is happiness to you?》(译林版)
2017届高考英语一轮复习检测:Unit1 Great scientists (人教版必修5)Word版含答案
2017届高考英语一轮复习检测:Unit3 The Million Pound Bank Note (人教版必修3)Word版含答案
2017届高三英语二轮复习 动词及动词短语教案(7)
2017高考英语一轮复习同步检测:M10 Unit 1~Unit 2(译林版)
2017届高考英语一轮复习检测:Unit1 Women of achievement (人教版必修4)Word版含答案
2017届高三英语一轮复习:Unit 5Rhythm 单元测试(北师大版必修2)
2017届高三英语一轮复习:Unit 4Cyberspace 单元测试(北师大版必修2)
2017高考英语暑假练习(13)(答案或解析)
2017高考英语一轮复习同步检测:综合卷 二(译林版)
2017高考英语阅读理解一轮(暑假)训练(4)及答案
2017高考英语一轮复习同步检测:M10 Unit 3~Unit 4(译林版)
2017届高考英语一轮复习检测:Unit5 Canada — “The True North” (人教版必修3)Word版含答案
2017届高考英语一轮复习检测:Unit3 Life in the future (人教版必修5)Word版含答案