The system protects internal organs from harmful bacteria, sunlight, and injury.

List three reasons people may begin using tobacco

Where are teens exposed to ads about tobacco products? on the radio in magazines near schools on television

Mason joined the water polo team at his school. as part of his conditioning, mason's coach requires a 25-minute run during practice. mason's heart rate reaches 125 beats per minute, but his target heart rate zone is 138—183 beats per minute. what should mason do to get the most benefit for his heart? increase the amount of time he runs increase the speed at which he runs decrease the amount of time he runs decrease the speed at which he runs