n my hometown,the air is polluted seriously.However,in recent years,the pollution gets from bad to worse,because of the increasing number of private cars.Especially during the rush hours,too many private vehicles move slowly on narrow roads,emitting a large amount of waste gas.Moreover,the poisonous gas sent by the nearby factories is also one of the main causes of pollution.Therefore,it’s demanded that immediate and effective measures must be taken to restrict private cars and public transportation must be developed to the largest extent.Besides,we should use renewable and clean energy recourses.