How does the stomach work with other systems to keep the body healthy?

First to answer will be the brainliest i need the answer asap

Which of the following statements about the societal costs of tobacco use is true? a. tobacco use affects the tax rate of only those individuals who smoke. b. the negative effects of tobacco use are only experienced by the smoker. c. tobacco users contribute to an overall loss of productivity. d. increased healthcare costs are mainly absorbed by tobacco users

Ihave a really high metabolism and only weigh 70 pounds (13 almost 14). people always ask me two questions: do you ever eat and how do you eat so much and stay so skinny.i am worried that a high metabolism wont me forever. what are some safe steps i can take to maintain being fit. (also, i already work out i am a dacer so i get cardio a lot)