posted by AK .
Which one of these statements is true regarding blood circulation?
A. For health and survival, it's critical for blood circulation to be ongoing and uninterrupted.
B. Normally, blood circulates in a repeating stop-start rhythm.
C. The heart deoxygenates blood that's returned to it.
D. Taking in large quantities of oxygen makes the circulatory system less efficient.
i don't know this one can you help?
It is A!