The level of serotonin in the brain is a decreased by a diet high in calories. b decreased by a diet high in salt. c increased by a diet high in protein. d increased by a diet high in carbohydrates. e decreased by a diet high in sugar.

The dietary guidelines for americans recommend (a) avoiding smoking. (b) engaging in aerobic exercise for 60 minutes at least five days a week. (c) making all of your grain choices whole grains. (d) increasing your intake of fruits and vegetables.

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).

China was the world's leading steel producer in 2006. what changes would you expect to be taking place in china?