II)
1. The dead fish are floating in the water.
2. Do you know what pollutants cause air pollution?
3. The river is contaminated by the dumping from nearby factories.
4. Noise pollution can also lead to headaches and high blood pressure.
III)
1. The air is so dirty. I sneeze so much. → If the air is so dirty, I will sneeze so much
2. Their children have birth defects. The parents were exposed to radiation.→ Their children have birth defects because the parents were exposed to radiation.
3. .The air pollution causes breathing problems→ The air pollution leads to breathing problems.