People all over the world today are beginning to hear and learn more and more about th

e problem of pollution.Pollution is caused either by man s release of completely new and often artificial substances into the environment, or by releasing greatly increased amounts of a natural substance, such as oil tankers into the sea

Whatever it' s underlying reasons, there is no doubt that much of the pollution caused could be controlled if only companies, individuals and governments would make more efforts In the home there is an obvious need to control litter and waste Food comes wrapped up three or four times in packages that all have to be disposed of: drinks are increa singly sold in bottles or tins which cannot be reused.This not only causes a litter problem, but also is a great waste of resources, in term of glass metals and paper.Advertising has helped this process by persuading many of us not only to buy things we neither want nor need, but also to throw away much of what we do buy Pollution and waste combine to be a problem everyone can help to solve by cutting out unnecessary buying, excess consumption and careless disposal of the products we use in our daily lives.

21.The main cause of pollution is

A the release of artificial or natural substances into the envIronment

B.the production of new industrial goods

C.increased amounts of a natural substance

22.Much of the pol lut ion could be controlled if only

A.people would pay more attention to the problem

B.governments would take effective measures

C.all sides concerned would make more efforts

23.Food packages, bottles and tins for drinks can cause

A.air and water pollution

B.both a litter problem and a waster of resources

C.to pay for the service

24.Which of the following cannot help solving the problem of pollution？()

A.Cutting out unnecessary buying

B.Eating.

C.Reduce excess us

25.What does the underlined word "litter" mean in Para.2？()

A.not many

B.serious problem

C.bits of waste things