Here are the sentences formed from the prompts:

6. We suggest growing more trees in the park to improve air quality.

7. The government should consider fining people who cut down trees.

8. I always avoid touching rocks in caves because it can spoil rock formations.

9. If we keep littering into the river, the water will not be safe to drink.

10. If people do not stop polluting the air, we will have lots of health problems.