Explanation:
The respiratory system allows for intake of oxygen, food 4 cells 2 absorb through the circulatory system.
once food is digested, it runs through the circulatory system as glycogen, (sugars). cells can readily absorb glycogen bcause of the fact it has smaller molecules 4 cells to absorb, to give them energy to function normally. respiratory system and the pulmonary aorta, distributes through the heart, absorbs food 4 heart, and distribute glycogen 2 rest of body, 4 cells 2 absorb 4 energy... hope this is helpful..
For adult it is 30:2 and for children it is 15:2