1900年北京城“坊市萧条，狐狸昼出，向之摩肩击毂者，如行虚墓间矣。”这种景象的

We often read 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	Moderate (适中)	Air quality is fine for most people.
Orange	101-150	Unhealthy for sensitive(敏感的) groups	Active children and adults and people with lung(肺) 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.

小题1:If the weather report says today’s AQI is 39, we can ________.

A．enjoy the clean air	B．spend less time outside
C．try not to go outside	D．stay inside most time

小题2:If the Air Quality Index is ______, the air quality is good for most people.

A．orange

B．red

C．purple

D．yellow

小题3:The _______ AQI numbers are, the _______ air quality is.

A．bigger; better

B．bigger; nicer

C．smaller; better

D．smaller; worse

小题4:We use ________ to tell about the quality of the air .
① color  ②words   ③weather   ④numbers

A．①②③④

B．①②③

C．①②④

D．②③④

小题5:Which of the following is TRUE?

A．If the AQI number is 140, the AQI colour will be red.

B．If the AQI colour is purple, the air is the best for people.

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

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