2. a) 1. We mustn`t pollute rivers.
2. We must use only unleaded petrol.
3. We must recycle paper, glass, etc.
4. We mustn`t create so much rubbish.
5. We mustn`t destroy rainforests.
6. We must protect wildlife.
7. We mustn`t drop litter on beaches.
8. We mustn`t let factories pollute the air.
b) If we recycle paper, glass, etc, we will save important resources.
If we didn`t create so much rubbish the planet would be cleaner.
If we didn`t destroy rainforests rare animals and plants would survive.
If we protected wildlife we will save andangered species.
If we didn`t drop litter on beaches, beaches would be clean and safe.
If we didn`t let factories pollute the air th atmosphere would be cleaner.