You may be offered hip replacement surgery if: 1  you have severe pain, swelling and stiffness in your hip joint and your mobility is reduced. 2  your hip pain is so severe that it interferes with your quality of life and sleep. 3  everyday tasks, such as shopping or getting out of the bath, are difficult or impossible.
The Earth consists of four concentric [concentric: Describe shapes (usually circles) which share the same centre point.] layers: inner core, outer core, mantle [mantle: A zone of hot rock in the interior of the Earth, located between the outer crust and the molten core.] and crust [crust: The outer
The highest layer of earths atmosphere is the exosphere. The inner core has the most or highest amount of density (iron/nickel). I think its the core of the Earth with highest temperature with  6000 degree Celsius. The crust is the layer of the Earth that has the the lowest density. It depends a bit on what you consider being a part.