完形填空（共20小题；每小题1.5分，满分30分）
In the past, man didn’t have to think about the protection of his environment. There were few people on the earth, and natural resources seemed to be   1  .
Today things are  2  , and the world has become too  3  . We’re using up our natural resources too quickly, and at the same time we are   4  our environment with dangerous chemicals. If we continue to do this, human life on the earth   5 survive.
Everyone 6  today that if too many fish are taken from the sea, there will soon be none left. Yet, with modern fishing  7, more and more fish are caught. We know that if too many trees are cut down, 8  will disappear and nothing will grow on the land. Yet, we 9  to use bigger and more powerful machines to  10  more and more trees.
We know that if rivers are polluted with waste products from factories, we’ll die.   11  , in most countries wastes are   12  put into rivers or into the sea, and there are  13   laws to stop this.
We know, too, that if the   14   of the world continues to rise at the present rate, in a few years there will not be enough  15  . What can we do to solve these problems?
If we eat more vegetables and less  16  there will be more food available for every one. Land that is used to grow crops 17  five times more people than land where animals are kept.
Our natural resources will   18   longer if we learn to recycle them.
The world population will not rise so quickly if people use modern methods of birth 19  .
Finally, if we educate people to think about the problems, we shall have a better and cleaner   20 in the future.

A．beautiful B．unlimited C．rare D．valuable

A．common B．the same C．changeable D．different

A．crowded B．small C．dirty D．busy

A．protecting B．saving C．polluting D．fighting

A．may not B．will not C．shall not D．could not

A．wonders B．realizes C．considers D．discovers

A．poles B．boats C．methods D．ideas

A．mountains B．seas C．trees D．forests

A．continue B．have C．ought D．go on

A．cut away B．cut off C．cut up D．cut down

A．Thus B．However C．Generally speaking D．Therefore

A．still B．even C．also D．certainly

A．too many B．a few C．some D．few

A．production B．pollution C．population D．revolution

A．houses B．vegetables C．food D．lives

A．fruit B．meat C．fish D．grain

A．feeds B．increases C．supplies D．helps

A．use B．stay C．keep D．last

A．control B．born C．place D．reward

A．star B．sea C．planet D．forest