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. I think pollution is not only the problem of our city, but also the problem of all the cities in our country and even in the world. And it’s not only the duty of the people in our city, but also of all the people on the earth to protect the environment, because we have only one earth. Do it from now on. Do it from every small thing around us. Then we will have a more beautiful and cleaner earth.