The second statement best explains the type of blood vessel and the function of these vessels' valves - <span>These are veins, which prevent the backflow of blood because the walls have little muscle to pump blood back to the heart.
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Veins are large blood vessels which carry blood back to the heart. <span>Veins have a system of valves to prevent back-flow.</span>
Answer:
the last answer makes sense
Answer:
because of their metsbolism
Explanation:
people who are more physically active tend to have a faster metabolism than those who are not. thus, their bodies break down foods faster and process those nutrients at a quicker pace than the latter.
Answer:
where's the question girl? what we have to ans..
