1, Air enters the body through the nose or mouth., 2, The air goes down a tube called the trachea., 3, The trachea splits into two tubes called the bronchi., 4, The bronchi divide into many smaller tubes called bronchioles inside the lungs., 5, The air reaches tiny air sacs called alveoli in the lungs., 6, In the alveoli, oxygen passes into the blood through tiny tubes called capillaries., 7, The blood brings carbon dioxide back to the lungs. We breathe it out.Breathe air out.

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