1.If we (recycle)  ________ more, we will help the Earth.

2. Factories (not dump) ______________waste into rivers if the government fine them heavily.

3. If people travel to work by bus, there (be)  ______________fewer car fumes.

4. We (save)  ________________thousands of trees if we don’t waste paper.

5. If we use water carefully, more people (have) ______________fresh water.

6. If the factory ( continue) ________________ dumping poison into the lake, all the fish and other aquatic animals will die.

7.If we recycle more, we (help) ________________ the Earth.

8. If people (travel)________________to work by bus, there will be fewer car fumes.

9. If he (study) ________________  harder, he can pass an exam.

10. She may be late if she (not hurry) ________________.

11.If you study harder, you (pass) ________________  the exam.

12. If you are kind to me, I (be) _______________  good to you.