完形填空．

通读下面短文，掌握其大意，然后从短文后各小题所给的选项中选择最佳的一项．

　　Hundreds of years ago, life was much harder than 1 today. People didn't have modern machines. There was no modern medicine, either.

　　Life today has brought new problems. One of the biggest is pollution. Water pollution has 2 our rivers and lakes dirty. It kills our fish and affects(影响) our drinking water. Noise pollution makes us talk louder and 3 . Air pollution is the most serious kind of pollution. It affects 4 living thing in the world.

　　Cars, planes and factories all pollute our air every day. Sometimes the pollution is so 5 that it is like a quilt(被子) over a city. This kind of quilt is called smog(烟雾).

　　Many countries are making new laws to fight pollution. Factories must now clean their water 6 away; they mustn't blow dirty smoke into the air.

　　We need to do many other things. We can put waste things in the dustbin(垃圾箱) and not throw them on the ground. We can go to work by bus 7 with our friends in the same car. If 8 people driving, there will be less pollution.

　　Laws are not enough. Every person must help to fight pollution.

1．

[　　]

2．

[　　]

3．

[　　]

A．feel happy more quickly

B．get angry much easier

C．become angry more easily

D．feel sad more slowly

4．

[　　]

5．

[　　]

6．

[　　]

A．before they are thrown

B．when they are thrown

C．after it is thrown

D．before it is thrown

7．

[　　]

8．

[　　]