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 (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.

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（建筑物）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.

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.

2.The underlined word “shoot” in the 2nd paragraph means “_________”.

A．send for

B．move quickly

C．come out

D．grow quickly

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 away

D．everything outside buildings would fly off into space

4.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 book

 

Answer 1

【答案】

1.A

2.B

3.B

4.D

【解析】

试题分析：这篇短文中讲述了两个科学常识。一是为什么飞机向西飞比向东飞用的时间长。而是一旦地球引力消失会发生什么事情。

1.根据The reason for the difference is an atmospheric phenomenon (大气现象) known as the jet stream (气流).及下文描述可知选A。

2.结合下文at a great speed可知选B，快速的移动。

3.根据‘Turning off’ gravity would be like letting go of the string.及上文描述可知选B，树木和建筑也不是那么容易的飞走。

4.这是一篇有关天文地理的知识性短文，最有可能在学生课本上见到，故选D，为最佳答案。

考点：关于科普性说明文的阅读

点评：阅读短文时注意文中对两种科学现象的说明，注意分析其表达的含义，注意通过上下文之间的连词，分析句子关系。有些问题的答案需要结合相关语句认真分析才能得出答案，故答题前一定要多读几遍短文。然后在带着问题在文中寻找信息，完成阅读。