Answer:
A
Explanation:
as the cell volume increases , its ability to exchange materiala across the cell surface increases
 
        
             
        
        
        
Answer:
C. capillaries connect arteries and veins.
Explanation:
A is false, veins carry blood towards the heart.
 B is false because arteries are the thickest blood vessel.
C is completely true
D is false, heartbeat is controlled by electric impulses