Where does the wind come from? What makes the wind move all the time? Scientists tell us that it is the sun that makes it move, and makes it blow. When the sun shines on the earth, it makes the earth hot. Then the earth makes the air hot. When the air becomes hotter, it also becomes lighter. The light air goes up. Cool air comes in to take the place of(代替) the hot air. The hot light air goes up higher and higher until it becomes cool. Then it comes down again, and then the earth makes it hot again, and it has to go up. When the air moves, we have wind.

【1】What makes the wind move?

A. The air. B. The sun. C. The earth D. The cloud.

【2】"When the air becomes hotter, it also becomes lighter." Here "it" means "_______".

A. the sun B. the wind C. the earth D. the air

【3】Which is TRUE?

A. The hot air is heavier than the cool air.

B. The cool air goes up to take the place of the hot air.

C. The air moves to make the wind.

D. On rainy days we can never feel wind.

【4】Which is the right order according to the passage?

a. The earth makes the air hot.

b．The hot air goes up.

c. The sun shines on the earth.

d. The hot air becomes cool.

A. a-b-c-d B. b-a-c-d C. c-a-b-d D. d-a-b-c

【5】The passage mainly tells us_______.

A. how the wind comes out B. what the wind is

C. when we have the wind D. when the air becomes hot