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.
【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 quickly

C．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 away

D．everything outside buildings would fly off into space

【小题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

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 (建筑物) 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 around your head on a string (细绳), it goes around in a circle until you let go of the string. Then it flies off in a straight line. ‘Switching 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. 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 word “shoot” underlined in the 2nd passage probably means “__________”.

A．send for                              B．move quickly

C．come out                             D．grow quickly

3.It can be inferred 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.Which of the following statements 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．Everything on the earth will float away if there’s no gravity.

D．Everything not attached to the earth would fly off in a straight line.

5.Where can we most probably read this text?

A．In a research paper.

B．In a short story.

C．In a travel magazine.

D．In a student’s book.

 

What is the sky？ Where is it？ How bright is it？ What lies above it？ These questions are difficult to answer, aren’t they？

　　Is the sky blue？ The sky has no color. We know that there is air around the world. When planes fly, they need air to lift their wings. Planes can’t fly very high because the air gets thinner when they go up higher. If we go up about 1,200 kilometers from the earth, we’ll find no air there.

　　When we talk about the sky, we usually mean the atmosphere around the earth. It is like a very thick “cover” over the earth and keeps it warm. Without the “cover”, the earth would be a very cold place and nothing could live on it.

　　Looking up above us, you will see the blue sky with white clouds. It is usually light blue, but the sky would be dark blue if you go to the top of the highest mountains. And you will see fewer clouds between you and the sun.

　　And if you sit in a spaceship high above the earth, there is no air at all. The sky would be so dark that its color would be black.

　　Sometimes the sky doesn’t look blue. When the sun rises and falls, you will see red, orange, and other colors in the sky. These are the most beautiful moments of the day.

　　Now you may understand that we see colors because the air scatters (散射) the sunlight. Light travels through the air. Without air, there would be no light and no colors.

1.Planes can’t fly very high because ____________.

A．there is air around the world

B．the air gets thinner when they go up higher

C．it’s warmer in the sky

D．the air gets thicker when they go up higher

2.We can see colors of the sky because ____________.

A．the sun rises and falls every day

B．the sky has lots of colors

C．the air scatters the sunlight

D．the sunlight has many colors

3.Which of the following is TRUE？

A．There is little air without light and colors in the sky.

B．The sky will look red, orange and other colors at noon.

C．The sky has only one color when the sun rises and falls.

D．The sky is dark blue if you go to the top of the highest mountains.

 

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

 

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 (建筑物) 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 around your head on a string (细绳), it goes around in a circle until you let go of the string. Then it flies off in a straight line. ‘Switching 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. 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 word “shoot” underlined in the 2nd passage probably means “__________”.

A．send for	B．move quickly
C．come out	D．grow quickly

【小题3】It can be inferred 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

【小题4】Which of the following statements 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．Everything on the earth will float away if there’s no gravity.

D．Everything not attached to the earth would fly off in a straight line.

【小题5】Where can we most probably read this text?

A．In a research paper.

B．In a short story.

C．In a travel magazine.

D．In a student’s book.