Which structure of the heart acts like an automatic door that closes once blood enters a chamber and forces it to exit in the pr
oper direction. A. Atria C. Arteries B. Valves D. Ventricles
2 answers:
Valves, they are like flaps of muscle that keeps the blood in its place util its ready to be pumped along.
Answer:
anwser is B: valves
Explanation:
You might be interested in
Option C. Organisms were probably more complex during past eras.
Mitochondria
...................................
Answer:
d wave length
Explanation:
The correct answer would be D
