Answer:
C
Explanation:
I hoped it help u out. Ur welcome :)
The respiratory system works directly with the circulatory system to provide oxygen to the body. Oxygen taken in from the respiratory system moves into blood vessels that then circulate oxygen-rich blood to tissues and cells.
The place where these molecules fit is called the active site .
The cells would be dividing all the time. Hope this helps
The random movement of molecules across a concentration gradient until the difference in concentration between two regions is near zero.
Im thinking it's active transport :) hope it helps.