What is a benefit of increased physical fitness?

How do the uv rays cause damage?   what exactly causes the skin to burn;   can you be more specific about this mechanism?   3. how do photosensitive medications increase a person's sensitivity to sunlight and therefore increase their risk of getting burned?     what kind of medications can increase photo-sensitivity, can you think of some examples?

Claustrophobia is an example of a(n)

Which of the following is a health risk associated with ground-level ozone? a.cataractsb.skin cancerc.respiratory illnessd.all of the above