How to be green 帮我用这个写篇英语作文!

how to be green?it is a good poblom,i want to be green,i cando many things,such as i can save the paper metal and glass,it is useful to dothis.and i can use water again.i can say there are a lot of thing to do for envoroment(环境).this all.
环境这个词书上有,我的不对