Answer: ensure blood flows toward your heart
Explanation:
These valves are what ensure blood flows toward your heart. Vein valves work hard, against gravity, to bring the blood that flowed down via arteries back up to your heart. When your vein valves are open and healthy, they are able to do their job properly, as the blood is easily able to flow up.
Answer:
C
Explanation:
because i took the test and got it right
In science, trait refers to a characteristic that is caused by genetics. Having green eyes or being shorter than average are traits a person might have. In more general use, a trait is an important part of someone's personality or appearance.
Multicellular organisms have a hierarchical structure organization, in which anyone is made up of numerous parts and is itself a component to the next level.
The brain stem helps regulate the flow information between the brain and the rest of the body
