Labels:book | bulletin board | concert | hakham OCR: Y AWNING AWNING fills your lungs and tiredness, triggers a yawn. which forces blood with the oxygen that gives oxygen -rich air into your lungs. The you strength and energy period of oxygen passes into your blood which shallow breathing perhaps caused by then transports around your body High ca arbon dioxide levels in your blood trigger yawn, forcing your mouth wide open Mouth Oxygen -rich air rushes into your lungs tc regenerate your blood Lungs 7AWNING lung carbon