Have you ever wondered?Why do airplanes take longer to fly west than east?It can take five

Have you ever wondered?
Why do airplanes take longer to fly west than east?
It can take five hours to go west-east from New York (NY) to London but seven hours to travel east-west from London to NY. The reason for the difference is an atmospheric phenomenon (大气现象) known as the jet stream (气流). The jet stream is a very high altitude (= above sea level) wind which always blows from the west to the east across the Atlantic. So the planes moving at a constant air speed go faster from the west to the east when they are moving with the wind than in the opposite.
What would happen if the gravity on Earth was suddenly turned off?
Supposing we could magically turn off gravity. Would buildings and other buildings float away? What happened would depend on (依靠) how strongly the things were attached (吸附) to the earth. The earth is moving at quite a speed, moving at over a thousand miles per hour. If you turn something around your head on a string, it goes around in a circle until you let go of the string. Then it flies off in a straight line. ‘Turning off’ gravity would be like letting go of the string. Things not attached to the earth would fly off in a straight line. People in buildings would suddenly shoot upwards at a great speed until they hit the ceiling (= top surface of a room). Most things outside would fly off into space.
【小题1】What information can we get from the first passage?A．It is the jet stream that affects how fast airplanes fly.B．Planes go slower when they are moving with the wind.C．It takes more time to fly from NY to London than from London to NY.D．The jet stream always blows from the east to the west across the Atlantic.【小题2】The underlined word “shoot” in the 2nd paragraph means “ ”.A．send for B．move quicklyC．come out D．grow quickly【小题3】It can be known that without gravity .A．buildings and other structures would float away B．trees and buildings would not so easily fly off C．something around your head would not float awayD．everything outside buildings would fly off into space【小题4】Which of the following is not mentioned in the passage?A．It takes seven hours to travel from London to New York.B．The earth is moving at a high speed.C．Things on the earth will float away if there’s no gravity.D．Things not attached to the earth would fly off in a straight line.【小题5】Where can we read this passage?A．In a research paper. B．In a short story.C．In a travel magazine.D．In a student’s bookA

(答案→)A 解析：这篇短文主要介绍了飞机为什么向西面飞比向东面飞花的时间更长的原因是气流的方向。还介绍了没有了地球引力会发生什么。【小题1】归纳总结题。根据短文第一段主要讲述了飞机为什么向西面飞比向东面飞花的时间更长的原因是气流的方向，故选A。【小题2】词意猜测题。A派人去请B快速运动C出来D快速生长，根据第二段People in buildings would suddenly shoot upwards at a great speed until they hit the ceiling (= top surface of a room). Most things outside would fly off into space.描述在建筑里的人会突然以一个巨大的速度向上移动直到他们撞上天花板。很多东西会飞到外太空。故选B【小题3】推理判断题。根据第三段What happened would depend on (依靠) how strongly the things were attached (吸附) to the earth.描述发生了什么将取决于东西连接到地球上有多结实。再根据后面描述可知树以及建筑不像其他物品那样容易飞出。故选B【小题4】细节理解题。根据短文描述，只提出了问题：关掉引力，建筑和其他东西会漂走吗？没有提及没有引力地球上的东西将会漂移。故选C。【小题5】出处猜测题。根据四个选项，A研究论文B小故事C旅游杂志D学生课本，这是一篇科普短文，有可能来自学生课本，故选D。

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