Labels:light | monitor | person | rock | sconce | toll line | traffic light | tree OCR: HELP Composition of Bones Page Bones are an. of layers of tissue 01 a Bone Cross Section A layer of spongy bone with lots" .of little holes Marrow cavity filled with fat and blood -vesse Perios teum, made Of tough fibres and cells Layer of-hard compact bone that gives strength. hole vessels
