It is very important to deal with the rubbish in cities.For one thing, rubbish may cause a lot of pollution.It may pollute the air, the water and the places we live in.For another, it may do harm to people's health.

　　处理城市垃圾是一个非常重要的问题。首先，垃圾会导致污染。它会污染空气、水和人们居住的场所。其次，它会危害人类健康。