Sacs in the lungs where oxygen diffuses into the blood and carbon dioxide diffuses into the air

The answer is areoles

Diffusion of oxygen into the blood takes place at the alveoli (air sacs). The air in the alveoli contains a lot of oxygen. The alveoli are very close to capillaries, which are small blood vessels. The blood in the capillaries has very little oxygen and has a lot of carbon dioxide.

The Answer Is:
~Alexander the Great's main impact on Western Civilization was that he helped to create Hellenistic culture and definitely was the cause of its spread throughout the Middle East. His conquests, and those of his father, helped to destroy the classical Greek civilization.

Hope this helps.