题目内容：

阅读理解。

Have you ever paid attention to the Air Quality Index(空气质量指标) or AQI reported in the newspaper? The AQI helps us understand what the air quality around us means to our health. The AQI uses colors, numbers and words to tell us about the air. Let’s see what these colors and numbers mean.

AQI colors	AQI numbers	Health word(s)	What to do
Green	0-50	Good	Just enjoy the clean air!
Yellow	51-100	Mederate(适中)	Air quality is fine for most people.
Orange	101-150	Unhealthy for sensitive(敏感的) group	Active children and adults and people with lung disease should spend less time outdoors.
Red	151-200	Unhealthy	People with lung disease and active kids and adults shouldn’t spend too long time outdoors. Everybody else should try to spend less time outside.
Purple	201-300	Very unhealthy	People with lung disease and active kids and adults should not spend any time outdoors. Everybody should try not to go outside.

1.If the Air Quality Index is _______, the air quality is good for most people.

A. orange        B. yellow

C. red          D. purple

2. When the AQI color is green, the AQI number may be___________.

A. 40           B. 80

C. 120          D. 160

3. The ______ AQI number are, the ______ air quality is.

A. bigger; better       B. bigger; nicer

C. smaller; worse       D. smaller; better

4.The doctor advises Mr. Zhang________ if the AQI number is between 151 to 200 because of his lung disease.

A. to stay outdoors often for fresh air

B. to spend less time outdoors

C. not to stay outdoors for a long time

D. never to spend any time outdoors

5. Which of the following is TRUE?

A. If the AQI numberis 140, the AQI color will be red.

B. People with lung disease are very sensitive to the air.

C. If the AQI color is purple,the air is the best for people.

D. The AQI can’t help people know the air quality.