Answer:
I believe this would be The Scientific Method
Explanation:
-it transports nutrients in the body
-it circulates macrophage in the body
Answer: D. I, II, III, IV, V, and VI
Explanation:
Oxygen is recquired for cellular respiration and break down nutrients like sugar to create ATP. Organisms from all kingdoms like Bacteria, Archea, Plants, Protists, animals and fungi can use cellular respireation.