Since the number before the tens place is 1, that means you will round the number down instead of up so your answer is :
4620
The answer is B. Speed up chemical reactions. Hope this helps.
Answer:Capillaries
Explanation: Capillaries are tiny, thin walled vessels that form a network to take blood through the organs and other body tissues. The dense networks of capillaries present a large surface area, which allows materials to be exchanged between body cells and the blood rapidly.
