Answer:
When you inhale (breathe in).
Explanation:
Air enters your lungs and oxygen from the air moves from your lungs to your blood. At the same time, carbon dioxide, a waste gas, moves from your blood to the lungs and is exhaled (breathe out). This process is called gas exchange and is essential to life.
I believe it is atom, then tree seedlings, then a cat, then a fence panel, then a pecan tree and lastly the house
This questions' answer is Both a and c
