Answer:
You didn't provide any answer choices.
Answer(..?):
Drilling or digging wells.
<span>The answer is valves. One </span><span>feature that the entrances and exits to the heart need in order to maintain this flow pattern is the valves. E</span><span>ntrances and exits to the heart may need valves in order to maintain this flow pattern. There are valves that control blood flow to the ventricles, and valves that control blood flow out of the ventricles.</span>
Answer: Homologous Structures
Explanation:
