It is important to beal with the rubbish in cities.Our world was colorful,beautiful and full of life.But these years,people have built many factories along rivers.Many trees have been cut down.Many animals have lost their homes.Factories cause pollution.Rivers become polluted.As a student,you should do every things in your everyday life to protect them.First,stop wasting more water.Second,throw waste things into different dustbins.For example,waste paper should be throw into paper recyclable bins.