Understanding the behavioral norms for each age and stage of development is important for interpreting behaviors and the correct application of guidance strategies.

Explain what causes the skin to burn in the sun? explain why people should avoid the sun if taking a photosensitive medication?

How harmful is it to smoke a pack of cigarettes a week?

Life expectancy in the united states is (76.4 for men and 81.1 for women). life expectancy is not the same as healthy life expectancy. healthy life expectancy is the number of years a person is expected to live in this number is obtained by subtracting years spent in poor health from overall life expectancy. the world health organization (who) calculates healthy life expectancy in 194 countries. the united states ranks twenty-ninth in the world using this measurement, with an average of of healthy life expectancy. singapore ranks number one (76 years), and japan is number two (75 years).