1. Student have to economize by _____________________ all the lights and fans before leaving their rooms.

    A. turning on       B. looking for        C. going on                     D. turning off

2. Farmers usually use ____________________ to kill insect and weeds.

    A. polluntants        B. pesticides          C. dynamite                 D. power

3. They have provided their children ________________ food.

     A. with               B. for            C. on          D. to

4. How about _______________ bottles and cans?

        A .reuse                   B. reused           C. reusing             D. reuses

5. Don’t _______________________ on the school yard

        A. prevent            B. receive           C. waste              D. litter