The left side of the heart performs the circulation

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?

Lori didn't want to learn the piano and thought her mom was wasting money on lessons. lori didn't like practicing and saw no future purpose for learning the piano since she wasn't going to grow up to be a pianist. what is lori expressing?

If your job requires you to use a respirator, your employer is required to do three things. what is missing from the list? have you medically evaluated to determine that it is safe for you to wear a respirator train you on how and when to use a respirator