Actually, the axial skeleton supports the head, neck, back, and chest and thus forms the vertical axis of the body. It consists of the skull, vertebral column (including the sacrum and coccyx), and the thoracic cage, formed by the ribs and sternum. The appendicular skeleton is made up of all bones of the upper and lower limbs.
A testable hypothesis must be just that--testable. You must be able to provide evidence that your hypothesis can be proven true in order for it to be considered accurate enough for future use among scientists. This can be done through repeated experimentation.