Question

Have you ever wondered?

1. 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 known as the jet(喷射) stream. The jet stream is a very high altitude wind which always blows from the west to the east across the Atlantic. The planes moving at a constant air speed thus go faster in the west-east direction when they are moving with the wind than in the opposite direction.

2. What would happen if the gravity on Earth was suddenly turned off?

Supposing we could magically turn off gravity. Would buildings and other structures float away? What happened would depend on how strongly the things were attached to the Earth. The Earth is moving at quite a speed, moving at over a thousand miles per hour. If you turn something round your head on a string, it goes around in a circle until you let 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. Most things would fly off into space.

1. What information can we get from the first passage?

A. The jet stream always blows from the east to the west across the Atlantic.

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. It is the jet stream that affects how fast airplanes fly.

2. The word “shoot” underlined in the 2nd passage probably means“ ______”.

A. send for       B. come out

C. move quickly   D. grow quickly

3. It can be inferred that without gravity _________.

A. trees and buildings would not so easily fly off

B. buildings and other structures would float away

C. something around your head would not float away

D. everything outside buildings would fly off into space

4. Where can we most probably read this text?

A. In a student’s book              B. In a short story

C. In a travel magazine              D. In a research paper

Answer

1.D

2.C

3.A

4.A

【解析】

试题分析: 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。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。

1.D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。

2.C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 shootupwards 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

3.A :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A

4.

考点：科普类阅读。