I need friends... Will you be my friend?

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?

This is one popular brand of exercise machine

What are the five food groups recommended by the usdas my plate food guidance system