Answer:
3. Bone marrow is a hollow space or deep cavity inside a bone where red, white blood cells and platelets are produced.
4. Your spine is important because, it connects all your nerves in your body to your brain and down to your feet.
5. Your ribs protect your heart and lungs. Your skull protects your brain.
6. 54 in both hands and 52 bones in both feet.
7. Joints-movement where bones meet.
