The Respiratory System

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Across
  1. 3. any of the major air passages of the lungs
  2. 7. a large membranous tube reinforced by rings of cartilage
  3. 9. where you can breath
  4. 10. a tube that has an internal diameter of hairlike thinness.
Down
  1. 1. the spreading of something more widely.
  2. 2. any of the minute branches into which a bronchus divides.
  3. 4. the part projecting above the mouth on the face of a person
  4. 5. carbon dioxide or other gaseous carbon compounds released into the atmosphere
  5. 6. each of the pair of organs situated within the ribcage
  6. 8. where the lungs and the blood exchange oxygen and carbon dioxide
  7. 11. each of a series of slender curved bones articulated in pairs to the spine