1. Air pollutants can do all of the following except:
   

A . damage the respiratory system

B . enter the bloodstream and harm other parts of the body

C . cause discoloration to your hair

D . reduce your protection from the sun's radiation

TRUE OR FALSE:

1. Biodegradable waste threatens the health of humans.
   

A . true

B . false

1. Some air pollutants are harmful to the ozone layer.
   

A . true

B . false