Once man did not h**e to think about the protection of his environment。 There were few people on the earth， and natural resources seemed to be unlimited。
Today things are different。 The world has bee too crowded。 We are using up our natural resources，and polluting our environment with dangerous chemicals。 If we continue to do this， human life on earth will not survive。
We realize that if too many fish are taken from the sea， there will soon be none left。 Yet，with modern fishing methods， more and more fish are caught。We know that if too many trees are cut down， forests will disappear。 Yet， we continue to use powerful machines to cut down more and more trees。 We see that if rivers are polluted with waste products， we will die。 Yet， waste products are
still put into rivers。
We know that if the population continues to rise at the present rate， in a few years， there wont be enough food。What can we do to solve these problems?
If we eat more vegetables and less meat， there will be more food **ailable。 Land for crops feeds five times more people than land where animals are kept。
Our natural resources will last longer if we learn to recycie them。
The world population will not rise so quickly if people use modern methods of birth control。
Finally， if we educate people to think about the problems we shall h**e a better and cleaner planet in the future。