- b) 1970 
- True 
- April 22nd 
- Air, water, soil/land, noise, thermal, radioactive, light, visual 
- b) Trees 
- Coal, oil, gas 
- a) Toxic 
- Because of the amount of water on the surface of the Earth 
- False: Too much carbon dioxide is harmful to the environment 
- a) Solar 
 
		
