It can be said that human beings are changing the environment in all respects through their ............. and by their .............

And they are destroying the air by adding ............. to it.

Thousands of .............. ............. all over the world have been established to protect endangered animals.

Human beings are changing the ............. by building cities and villages where forests once stood.

They are changing ............... by cutting down trees in the forests.

Scientists have made lists of ................ ................ and suggested ways to save them.

This has resulted in two serious ......... The first is that many kinds of rare animals are killed. The second is that the environment where these animals are living is badly ...............

As a result, the number of rare animals is decreasing so rapidly that they are in danger of becoming .................

Many other species ..................... on this planet.

The ................ is only one small species in the living world.

Human beings have a great .................. on the rest of the world.

The Earth will be a happy planet where human beings, animals and plants peacefully .......

Many organisations have been ............. and funds have been ..........