用方框中所给单词或短语的适当形式填空，使短文通顺、正确连贯，每个单词或短语限用一次。

can   help   ground    rather than    encourage    by   plant  we   off   unless

      
There are many ways to save the environment if you would like. In this passage, you can find some ways.
Plant more trees. Choose a right ________ near your house or workplace. ________ there’s any rule stopping you growing trees in that area, go ahead and grow trees. Plant a tree every month and________ your friends and classmates to join you. Have more and more trees ________ and there will come a day when you have green land thanks to your hard work.
Walk more and drive less. Choose to walk ________ drive your car. Walk or ride a bicycle to work if it’s not very far. Not only cycling but walking is good exercise. And each time you avoid using your car, you’re doing something ________ to cut down air pollution. You are saving fuel, saving money and keeping fit as well.
Save water. Water is very important for living things. It’s ________ who use and pollute it. The simplest way to save water is turning ________ water taps after use. When you visit a beach, make sure that you don’t throw waste around. Do not pollute rivers ________ dropping garbage or other waste. Water is so precious, so we ________ waste or pollute it.