Respiratory System

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Across
  1. 1. Flat bone located in the middle of the chest
  2. 4. Tiny balloon shaped air sacs
  3. 5. Activities that don't require oxygen
  4. 8. Process of taking in oxygen and getting rid of carbon dioxide
Down
  1. 2. Scientific name for chest
  2. 3. Main airway into the lungs
  3. 4. Activities that require oxygen
  4. 6. Byproduct of anaerobic respiration
  5. 7. Smallest blood vessel in the body