Green plays an important role in our daily life.So It is our responsibility to protect the trees and grass.In this way, we can spend our leisure time persuading people not to walk on the lawn.Maybe we should put a sign on the tree or insert a brand into the soil where planted lots of grass.Besides,we are also able to be devoted to planting some trees which will make our school more beautiful and make the air surrounding us fresh.

In a word,we should try our best to make our school clean and pretty.