The oxygen molecules moves through the nostrils, pharynx, trachea, bronchus, smaller and smaller branches of the bronchial tree, and then into the alveolus.
It allows scientists to explore new explanations for observations.
I think the answer to this is D.
Answer:
The average adult, when resting, inhales and exhales about 7 or 8 liters of air per minute. That totals about 11,000 liters of air per day. Inhaled air is about 20-percent oxygen. Exhaled air is about 15-percent oxygen.
Explanation:
