The Respiratory System

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Across
  1. 4. under the lungs
  2. 6. co2
  3. 8. major air passages of the lungs
  4. 9. the most important part of the respiratory system
Down
  1. 1. a tube where air gets in
  2. 2. an opening to our windpipe
  3. 3. tiny air sacs of the lungs
  4. 5. something that is waste in your body
  5. 7. protects your lungs