The principle of uniformitarianism is a a.) biased method of dating rocks. b.) complex method of dating rocks. c.) creative explanation for how rocks are made at present. d.) non-testable explanation of how rocks are made at present.

these muscles maintain the blood pressure in the vessels. the smooth muscles are innervated by nerves of the autonomic nervous system. when the muscles contract, they cause vasoconstriction of the vessels and increase blood pressure. when the muscles relax, they enable vasodilation of the   blood vessels hence reduce blood pressure.