we had a chemistry class yesterday, in which we learned about the importance of environmental protection. mr. zhao, who is our teacher, told us that he was very worried about the pollution in our city. he said that our city used to be a beautiful one with a very wonderful natural landscape, such as green mountains, clean water, fresh air and so on.

　　    but now, all of them are gone.

　　    have you ever littered? have you ever spat in a public place? have you ever drawn casually on walls? if your answers are “yes”, that means you have to do something to protect the environment. you can also ask yourself: “have i ever picked up dirty paper and thrown it into a dustbin? have i ever collected bottles for recycling? have i ever planted trees or flowers?” if your answers are still “yes”, that shows you’ve made a contribution to the environmental protection.