II

1.If the water temperature increases, some aquatic creatures will be unable to reproduce.

2.If the land is polluted, the farmers will be unable to grow crops.

3.If there were not so many billboards in our city, people could enjoy the view

III

1.plastic bags are a major source of waste ,so we should not throw them everywhere.

2.The air breathe gets polluted due to the factory fumes / fumes released from factories/ release of fumes from factories 

II.

1. If the factory didn't install a new filtration system, the industrial wasn't well-treated.

2. If the water temperature increases, some aquatic creatures will be unable to reproduces.

3. If the land wasn't polluted, the farmers will be unable to grow crops.

4. If there aren't so many billboards in our city, people can enjoy the view.

III.

1. Plastic bags are a major source of waste so we shouldn't throw plastic bags everywhere.

2. The air breathe gets polluted due to the fumes from factories.