Answer
That used to follow the movements of molecules in the cells.
Explanation:
Astronomers use the distancebetween Earth and sun, which is 93 million miles, as a new unit of measure called the Astronomical Unit. It is defined to be exactly 1.00 for the Earth-Sun orbit distance, and we call this distance 1.00 AUs.
The answer is artery.
A blood vessel with a thick layer of smooth muscle and elastic fibers is artery. Even though both artery and veins are smooth muscle and elastic fiber. The difference is veins have valves, while arteries don't.
