Playing a role in___ making___
possible.
providing
and support.

chemical reactions.

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.  

well, since there is no answer choices, i will give an answer on how it works : )

the two objects are placed together. energy will always be transferred from the hotter object to the cooler object until they are equal. hope this is close to one of the answer choices : )

essentially, one bacterial cell splits into two daugurer cells. bacterial offspring don't need or get care from their parents because they are in a sense their own parents. that said, some bacteria can and do depend on other bacteria especially in harsh environments such as bacterial microfilms in hot water tanks.