根据短文内容，用方框里所给单词的正确形式填空，使短文意思完整。每个空格只能填一个单词，每个单词只能用一次

Today, we still have some environmental problems. As a middle school student, we should do something to improve more environmental .

On the one hand, we ourselvesdestroy the environment, such as throwing the rubbish about. We canpart in some commonweal（公益）activities to plant more trees, for the trees are good to our environment. On the other hand, if someone does harm to the environment, like spitting on the ground or stepping on the grass, we can stop them from so, If there's a factory which destroys the environment, we can tell the relative（相关）department or the police about it.

All in all,  we are students, we can still do a lot to protect our environment, and we should take action from now on.