Respiratory system

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Across
  1. 3. Inside the lungs bronchi is further divided into_____
  2. 4. Prevents the food from entering the windpipe
Down
  1. 1. Muscles that help in the movement of the rib cage on inhalation and exhalation
  2. 2. Gas exchange in the lungs happens in ____
  3. 5. Common passage for food and air
  4. 6. Pair of spongy organs protected by the ribcage