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_小题1:____ of pollution that I worry about. The most terrible two are w__小题2:_  pollution and air p_小题3:______, 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 _____小题4:__ of polluted air. I think factories shouldn’t  pour dirty water i_小题5:_____ rivers directly or produce so much waste gas. We’d better go on  foot or by  bike  i____小题6:___ of by car. Finally, everyone must pay attention to r___小题7:___ pollution. If everybody makes so m__小题8:___ rubbish , one day we may live in a world which is full of rubbish. H__小题9: frightening it will be ! We should take a____小题10:__ to make our world cleaner and more beautiful.