the.com/nostrils
The face's twin chimneys, quietly running air through your nose since birth.
means The two openings of the nose through which air, smells, and the occasional sneeze travel.
from From Old English nosthyrl, literally nose-hole — thyrl meaning hole, cousin to thrill (which originally meant to pierce).
One at a timeNostrils alternate dominance hours apart, a nasal cycle.
Two smellsEach nostril samples scent at slightly different speeds.
Word relativeNostril and thrill share the same piercing root.