Air, dust, pollen, smoke, spores, viruses, small insects (sometimes), etc.
Well, you are inhaling in oxygen and giving off carbon dioxide. So as you inhale, air goes into your body. (Try taking a deep breath) C:
Oxygen and nitrogen
trachea
The Respiratory System does that work.
nose or mouth
mouth and nose
you become gay
no one does the air does it and we inhale it
You don't only "breath in air, and breath out air," You breath in Oxygen and let out Carbon Dioxide. Passes to the diaphragm and the lungs, inhale oxygen, it goes through your body, exhale Carbon Dioxide, From which the body has made when inhaled.
It goes into your lungs which absorb oxygen from it and expell carbon dioxide and then you breath it out. The oxygen goes into your blood to fuel everything in your body. it ends up in your lungs Pharynx--> Larynx--> Trachea--> Bronchus--> Bronchiole--> Aveolus--> Lung
Air enters the body when you inhale (Breathe in) air enters through the mouth and into the lungs. and then exhale (Breathe out) carbon dioxide (CO2)
CO2