Choose the correct option. 1. People must stop destroying forests so / because we need forests for oxygen. 2. Temperatures are increasing because / so there is global warming. 3. Cars emit exhaust fumes, because / so they make the air dirty and cause air pollution. 4. We must recycle plastic and glass, so / because we can reduce our waste and reuse them. 5. We should use renewable energy like solar energy so / because it is not harmful to the Earth.