ab is the answer please give me brainleist answer
The two semilunar valves, the pulmonary and aortic valves, are closed, preventing backflow of blood into the right and left ventricles from the pulmonary trunk on the right and the aorta on the left.
Answer:
a closed circulatory system.
Explanation:
an earthworm circulates blood exclusively through vessels.
Answer:
what are the two patterns?
