air passage

Finally, the fragile complexity hidden inside the human body — from the intricate webs of blood vessels to the gracefully branching air passages of the lungs to the delicate yet sturdy structure of bone — was there for all to see.

In the secondary system A is a cold-air passage, T a butterfly valve and J a gasoline jet discharging into the cold-air passage.

Each side of each137 flat water cell abuts on an air passage.

So much water can flow out that an air passage is left at a, and the pipe is not sealed.