carbohydrates
they are like fat but they are used in your body and hold water whitch makse people look bloted
Answer:
Gas exchange during respiration occurs primarily through diffusion. Gas molecules move from a region of high concentration to a region of low concentration. Blood that is low in oxygen concentration and high in carbon dioxide concentration undergoes gas exchange with air in the lungs.
Explanation:
Worms don't have lungs. They breathe through their skin.
Hope this helps. :)
The two subjects are both dealing with flesh, the human skin