1. It is necessary to use energy-saving bulbs instead of ordinary bulbs.

2. How about taking a shower instead of having a bath to save water.

3.I think we should turn off all lights and fans before leaving the classroom.

4.I suggest that you should reduce the amount of water your family use.

5. If we go on littering, the environment will become serious polluted.

6.Energy -saving bulbs should be used to save electricity.

7.You should reduce the amount of water your family use.

8.If we go on wasting water, there will be shortage of fresh water.

9.We can not go for a walk beacause it is rains heavily.

10.Many people are afraid that the river will be polluted by the factory.