Answer:
They deliver oxygen to the blood.
Explanation:
The main function of the respiratory system is to provide oxygen to the body and to remove carbon dioxide from the body. Oxygen is transported to all ports of the body via blood vessels from the lungs. The alveolar sacs, present in the lungs, allow oxygen to be transported to the blood and carbon dioxide to be taken up.
The organs of the respiratory system include nose, pharynx, epiglottis, larynx, trachea, Bronchi, Bronchioles, alveolar sacs of the lungs.
