第二节:完形填空(共20题:每题1.5分,满分30分)
阅读下面短文，掌握大意，然后从36～55各题所给的四个选项（A、B、C和D）中，选出最佳选项。
In the past, man did not have to think about the protection of his environment. There were few people on the earth, and natural resources seemed    36     .
Today things are    37    . The world has become too    38   . We are using up our natural resources too quickly, and the same time we are    39    our environment with dangerous chemicals. If we    40   to do this, human life on the earth will not survive.
Everyone    41     today that if too many fish are taken from the sea, there will soon be no fish left. Yes, with modern fishing    42   , more and more fish are caught. We know that if too many trees are cut down,    43    will disappear and nothing will grow on the land. But we continue to use    44   and more powerful machines to    45    more and more trees.
We realize that if rivers are polluted with waste products from factories, we will die.    46    , in most countries waste products are     47    put into rivers or into the sea, and there are    48    laws to stop this.
We know, too, that if the    49    of the world continues to rise at the present rate, in a few years, there will not be enough    50   . What can we do to solve these problems?
If we eat more vegetables and less    51    , there will be more food available for everyone. Land where we grow crops     52   five times more people than land where animals are kept.
Our natural resources will    53     longer if we learn to recycle them.
The world population will not rise so quickly if people use modern methods of birth    54    .
Finally, if we educate people to think about the problems, we shall have a better and cleaner    55    in the future.
36. A. beautiful         B. unlimited               C. little                  D. valuable
37. A. common         B. the same            C. changeable            D. different
38. A. crowded            B. small                       C. dirty                  D. busy
39. A. protecting        B. saving                C. polluting               D. fighting
40. A. try              B. continue             C. decide                 D. have
41. A. wonders         B. realizes                C. considers               D. discovers
42. A. poles            B. thoughts            C. methods                D. ideas
43. A. mountains        B. the sea                C. trees                  D. forests
44. A. bigger             B. less                 C. smaller                D. higher
45. A. grow up        B. plant              C. save                 D. cut down
46. A. Thus          B. However             C. Generally speaking      D. Therefore
47. A. still             B. even              C. also                   D. certainly
48. A. many              B. enough             C. some                 D. few
49. A. production       B. pollution         C. population             D. revolution
50. A. houses           B. vegetables           C. food                  D. lives
51. A. feeds            B. meat               C. fish                   D. grain
52. A. feeds           B. increases            C. supplies               D. helps
53. A. use               B. stay              C. keep                 D. last
54. A. control          B. born                  C. plan                  D. reward
55. A. nature            B. sea               C. planet                D. Forest