PDF chapter test TRY NOW

Give very short answers to the following question:
 
1. Combustion of fossil fuels generates a lot of air pollution. Can you suggest any two alternative sources of energy which do not cause any pollution?
 
The combustion of fossil fuels generates a lot of air pollution. energy and energy are two non-polluting alternative sources of energy.
 
2. Name any two water pollutants which are toxic for plants and animals.
 
and are two toxic water pollutants to plants and animals.