Those are really wacky answers to choose from. It isn't B.They are usually man made. It's not C. we still need to be careful. It is not D. It is always your responsibility for whatever you do. It shouldn't be A, but that would kind of make sense. I would choose A.
I believe it is A because i feel it is the only exercise were you are using your arms to lift you entire body off the ground, but who knows i could be wrong <span />
Answer: The lower respiratory system moves oxygen into the blood; the circulatory system delivers blood to the body.
Explanation:
