题目内容：

    The earth is our home. We must take care of it. Life today is easier than it was_______years ago, but it has brought some new problems. One of the biggest problems is pollution（污染）. We can see it, smell it, drink it and even_______it. Man has polluted the_______.The more people, the more pollution.Many years ago, the problem was not so serious because there were not so_______people. When the land was used up (用光), the river was not clean in a place,man went to_______place. Now man is slowly polluting the whole world_______pollution is still the most serious, it’s bad for_______things in the world.Many countries don’t le t people burn_______for air in houses and factories in the city. Pollution by SO2 is now the most dangerous kind of_______pollution. It’s caused by heavy traffic. People say it’s________to ride bikes. When you are________, there is no pollution. But even in developed countries, most people don’t go to work by bike. It’s not________bikes are expen sive or people are tired if they ride to work. It’s because the number of cars on the roads becomes larger. So more people________their bikes and go to work by cars, then things are getting________We should have special roads only for bikes and make it________difficult and expensive for drivers to take their cars into the city that they will go back to use their bikes.

1.A.hundred B.hundredsof C.hundredof D.hundreds

2.A.listen B.listento C.hearof D.hear

3.A.moon B.star C.earth D.sun

4.A.lot B.little C.many D.much

5.A.others B.the others C.the other D.another

6.A.Air B.Food C.Water D.Noise

7.A.life B.live C.living D.lives

8.

A.something bad B.bad something

C.something good D.good something

9.A.water B.air C.noise D.white

10.A.least B.best C.most D.worst

11.A.driving B.biked C.riding D.ridden

12.A.why B.because C.what D.how

13.A.puton B.lookat C.putaway D.lookup

14.

A.better and better B.more and more

C.worse and worse D.bigger and bigger

15.A.quite B.such C.very D.so