What are the minimum and maximum frequencies for exercise regimens?

As you sit in the library with your friend studying for your weekly quiz on the integumentary system, you come upon an article about the hazards of prolonged exposure to the sun's rays. your curious nature leads you to research the subject further. you're fascinated to learn that minimal exposure to the sun allows you skin to manufacture vitamin d, which is important to maintain homeostasis. you also read that although sunscreen can protect you from the ultraviolet (uv) rays of the sun, some medications can actually increase a person's sensitivity to the sunlight.

Minor illnesses: a.) decrease the risk of sids b.) increase the risk of sids c.) increase the risk of hospitalization d.) decrease the risk of allergies e.) increase the risk of allergies

In which book word demography is used for first time