body movements

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Across
  1. 2. modified forelimbs in birds
  2. 4. the joint present in the elbow
  3. 5. ribcage protects this organ
  4. 8. ball and socket joint is present
  5. 9. movement is possible due to contraction and expansion of these
Down
  1. 1. this joint joins the neck to the head
  2. 3. the movement of a snake
  3. 6. earthworm can move with the help of these
  4. 7. they are 206 in numbers
  5. 8. Outer skeleton of the snail