根据短文内容和首字母提示，在下文空格处填入适当的词使短文完整。
The environment is becoming worse and worse . There are  many k_____ of pollution that I worry about. The most terrible two are w___  pollution and air p_______, because people can’t live healthily with dirty water and polluted air. Animals can’t live in the world ,either. More and more people are becoming ill b _______ of polluted air. I think factories shouldn’t  pour dirty water i______ rivers directly or produce so much waste gas. We’d better go on  foot or by  bike  i_______ of by car. Finally, everyone must pay attention to r______ pollution. If everybody makes so m_____ rubbish , one day we may live in a world which is full of rubbish. H__ frightening it will be ! We should take a______ to make our world cleaner and more beautiful.