Smiling, shaking someone's hand, and saying "hello" are all ways of:

Maintaining a healthy weight allows the respiratory system to work more effectively because a. oxygen is being delivered more adequately. b. the heart does not have to pump as forcefully. c. the capillaries are constricted. d. the lung capacity allows for small amounts of air.

Condition of normal breathing called

Which of these is a sexual stereotype? a) on average, males are taller than females. b) people over the age of 60 are not interested in sex. c) male hormone levels differ from those of females. d) there are more male representatives than female representatives in congress.