I believe it’s carbon dioxide, because you use your respiratory system to breathe in oxygen, and oxygen goes through your circulatory system. And you breathe out CO2.
Advise Mr. Walker to call 911 and be seen in the emergency room. SOA, pressure in the chest and sweating (diaphoresis) are i indicators of heart attack. I would suggest a low dose of baby aspirin too to thin the blood in the event it is a heart attack.
The system that prepares food for absorbtion into the bloodstream is the digestive food. It makes sure the food in the stomach is broken down.
0% Children these days dont have any respect or even know how to lift a single finger without being told how to do that step by step ...
