To take air into your lungs and send it out again through your nose or mouth
breathe
To make water, air, gas, etc. flow in a particular direction by using a pump or something that works like a pump
pump
Two parts inside in the chest that you use for breathing
lungs
When you breathe in, what goes into your lungs?
Oxygen
The red liquid that goes around your body and keeps you alive
blood
When you breathe out, what goes back into the air?
Carbon dioxide