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 (大氣現象) known as the jet stream (氣流). 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】

試題分析：這篇短文中講述了兩個科學常識。一是為什么飛機向西飛比向東飛用的時間長。而是一旦地球引力消失會發(fā)生什么事情。

1.根據The reason for the difference is an atmospheric phenomenon (大氣現象) known as the jet stream (氣流).及下文描述可知選A。

2.結合下文at a great speed可知選B，快速的移動。

3.根據‘Turning off’ gravity would be like letting go of the string.及上文描述可知選B，樹木和建筑也不是那么容易的飛走。

4.這是一篇有關天文地理的知識性短文，最有可能在學生課本上見到，故選D，為最佳答案。

考點：關于科普性說明文的閱讀

點評：閱讀短文時注意文中對兩種科學現象的說明，注意分析其表達的含義，注意通過上下文之間的連詞，分析句子關系。有些問題的答案需要結合相關語句認真分析才能得出答案，故答題前一定要多讀幾遍短文。然后在帶著問題在文中尋找信息，完成閱讀。