I think the respiratory system and circulatory system
I guess that is:
Within the capillaries of the lungs, gases are exchanged by diffusion; O2 diffuses from the alveolus to the bloodstream and CO2 diffuses from the bloodstream to the alveolus.
Answer:
The atomic number of phosphorus is 15. It has zero charge because it has 15 electrons.
Explanation:
Most of Earth's carbon is stored in rocks and sediments.
