Good environment can make people feel happy. To improve the environment means to qualify our life . What should we do to improve our environment ?

　　We should plant more trees . And we should prevent those factories from pouring waste water into rivers , lakes and fields . Whenever we see litter on the ground , we should pick it up and throw it into a dustbin . Don’t spit in public places . Don’t draw on public walls . It’s our duty to keep our earth clean and tidy .