Superior vena cava- upper body inferior vena cava
lower body- bother drain into the right atrium
I think it's oxygen and water because they are the substance for cellular respiration.
In biology, a life cycle<span> is a series of changes in form that an </span>organism<span> undergoes, returning to the starting state. "The concept is closely related to those of the </span>life<span>history, development and ontogeny, but differs from them in stressing renewal."</span>
I hope this helps, good luck!