There are three kinds of blood vessels: arteries, veins, and capillaries. Each of these plays a very specific role in the circulation process. Arteries carry oxygenated blood away from the heart. They're tough on the outside but they contain a smooth interior layer of epithelial cells that allows blood to flow easily.
B. Placenta (works with the umbilical cord to provide nutrients to the developing human)!
Answer:
Six common themes in literature are:
Good vs. evil.
Love.
Redemption.
Courage and perseverance.
Coming of age.
Revenge.
Explanation:
I believe the answer is A
