<span>a: There is a unidirectional blood flow.
d: Arteries carry blood away from the heart.
e: Veins carry blood toward the heart.</span>
They should be kept in all of the above
I think maybe (B) because distress is when you have extreme anxiety or your extremely sad about something.
C. It just needs one parent.
Answer: The heart consists of four chambers, two atria (upper chambers) and two ventricles (lower chambers). There is a valve through which blood passes before leaving each chamber of the heart. The valves prevent the backward flow of blood.
