Answer:
For most people, a single set of 12 to 15 repetitions with the proper weight can build strength
and improve fitness as effectively as can multiple sets of the same exercise
Explanation:
The circulatory system is very useful. This system transports the food nutrients, and oxygen to the body cells. It also delivers of carbon dioxide and waste products. This helps the respiratory system by transporting nutrients to keep the lungs clean, and healthy.