मानव हड्डी के मैट्रिक्स की कठोरता मुख्य रूप से किस खनिज यौगिक की उपस्थिति के कारण होती है?

Which bone is located at the back/posterior part of the human pelvic girdle, forming the base of the spine?

How many pairs of 'false ribs' (including floating ribs) are present in the human skeleton?

The thin membrane that lines the inner surface of the bone within the medullary cavity is called the: