The lungs contain all of the alveoliepithelial cellslobulesbronchioles that move oxygen into the blood.

Alveoli are tiny air sacs in the lungs where gas exchange takes place. Oxygen passes from the air in the alveoli into nearby blood vessels. Bronchioles carry air toward the alveoli, while epithelial cells line surfaces and lobules are larger sections of lung tissue, so the best answer is alveoli.

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