Use the words given to fill in the blanks. There is one extra word that you do not need to use.
down – air – quickly – about – save - dirty – important – pollute – grow

    We all are destroying the Earth. The seas and rivers are too (1).......................... to swim in. There is so much smoke in the (2) ................................ that it is unhealthy to live in many of the world's cities. In one well-known city, for example, poisonous gases from car (3) ............................. the air so much that policemen have to wear oxygen masks. We have cut (4)......................... so many trees that there are now vast areas of wasteland all over the world. As a result, farmers in parts of Africa cannot (5) ......................... enough to eat. In certain countries in Asia there is so little rice. Moreover, we do not take enough care of the countryside. Wild animals are (6) ............................. disappearing. For instance, tigers are rare in India now. Because we have killed too many for them to survive. However, it is not so simple to talk (7) .............................. the problem. We must act now before it is too late to do anything about it. Join us now. (8) ..................the Earth.