respiratory system

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Across
  1. 1. the movement of gas molecules from higher concentration to lower concentration
  2. 4. diffuse from blood capillary to the alveoli
  3. 6. Windpipe
  4. 7. diffuse from alveoli to the blood capillary
  5. 8. smaller windpipe
Down
  1. 2. Oxygen into lungs
  2. 3. Air out of lungs
  3. 5. Tiny sac in lungs