11．The past fifty years or so have seen the gradual disappearing of animals from this earth，fishes from the sea，trees and plants from the land．
Many factors result in this unpleasant phenomenon．Among them，hunting is the main factor that endangers wild life．Some people kill wild life for sport．They take pleasure in collecting heads and hides．Yet others specialize in commercial hunting like killing whales．
Apart from this，the rapidly growing human population threatens wild life on land，too．Towns expand and roads have to be built，so forests are burnt and trees are chopped down．It seems that man needs every inch of land within his reach，so he moves on to the natural habitat of wild life．Tigers，lions and leopards slowly die off without the food and shelter that the forests provide．
In addition，rapid urbanization means industrial expansion．Very often，poisonous chemicals，industrial wastes and oil are dumped into the rivers and seas．Fish and birds are threatened．
Man depends greatly on animals for survival．He needs their flesh，hides and furs．Thus，man cannot do without wild life； or he himself would become extinct．The public should be made aware that it would be better to shoot the animals with a camera than with a gun．In this way，they can preserve and help wild life to continue living rather than to remove all signs of it．
Man must learn to farm the sea as he does the land．He should control the amount and the frequency of his catch．He should allow fish to breed and multiply before netting them．Man also needs to build forest reserves，and to pass laws prohibiting the killing of animals，especially those that are already rare．To keep the present animal kingdom，the least that man can do is to clean the seas and rivers and to prevent pollution．
The cycle of nature is such that it forms a vicious circle．The pesticides（杀虫剂） that we spray on crops can kill the birds and animals that feed on them．When man eats these poisoned animals，he himself can die．We must therefore test the chemicals to be used before they are sprayed or it might mean the death of man!
13．The author's purpose in writing the passage is toD．
A．explain how important wild life is to human beings．
B．call people's attention to serious problem of pollution．
C．explain relationship between wild life and human being
D．call people's attention to the protection of wild life
14．Which of the following is NOT true according to the passage？C
A．The growing human population threatens wild life because people take land from animals
B．Some people devote themselves to killing animals for money．
C．People can preserve and help wild life to continue living by shooting the animals with a camera．
D．Fishes are threatened by poisonous chemicals，industrial wastes and oil．
15．The last paragraph is mainly aboutA．
A．the importance of wild life to human beings
B．how the circle of nature is formed
C．how animals are gradually disappearing form the earth
D．how to solve the problem of pollution．
