Vital Functions of Bird

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Across
  1. 2. a way for birds to move
  2. 4. inner framework that offers support
  3. 7. how birds make more birds
Down
  1. 1. organs used for breathing
  2. 2. provides protection for the bird
  3. 3. another word for breathing
  4. 5. a _____-shelled structure that protects eggs
  5. 6. limbs adapted for flying
  6. 8. a bird's heart is divided into four of these