Breathing

People can breathe.

People breathe through their mouth and nose.

People breathe in air.

Air has oxygen.

Air goes into the lungs.

The lungs bring the oxygen to the blood.

The blood brings oxygen to the body.

Lungs breathe out carbon dioxide.

Carbon dioxide is waste.

Waste is something we cannot use, like garbage.

The lungs bring in oxygen to the body.

This part of the body is called the respiratory system.