What role does safety play when you apply the principle of overload?

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.

In which way does nicotine cause addiction? by stimulating the brain’s pleasure center by increasing blood-sugar levels by decreasing dopamine levels by reducing depression and anxiety

Summarize four pregnancy-prevention methods. discuss the benefits effectiveness and risks of each