Bones consist of living cells embedded in a mineralized organic matrix. This matrix consists of organic components, mainly type I collagen – "organic" referring to materials produced as a result of the human body – and inorganic components, primarily hydroxyapatite and other salts of calcium and phosphate.
The circulatory system - hemoglobin in the blood transports oxygen :)
A magnifying glass is an example of a simple microscope. The correct answer is will be D, simple microscope.
