Answer:
1. If we recycle more, we will help the Earth.
2. Factories will not dump waste into rivers if the government fines them heavily.
3. If people travel to work by bus, there will be fewer car fumes.
4. We will save thousands of trees if we don't waste paper.
5. If we use water carefully, more people will have fresh air.
6. If the factory continues dumping poison into the lake, all the fish and other aquatic animals will die.
7. If I go out tonight, I will go to the cinema.
