Answer. Form of exercise.
Explanation: Tennis is a good exercise and good for interacting with others. Also can be for all ages
Red blood cells pick up oxygen in the lungs. Blood travels away from the heart and lungs through the arteries. Red blood cells drop off oxygen to the cells through tiny tubes called capillaries. Blood then returns to the heart through the veins and the cycle begins again.
It keeps us healthy and active. Without water you can become dehydrated and eventually run out of energy.
Where are the answer choices???
<em>The answer is:</em> Cardio Training
