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
MANTLE -- The mantle is a dense, hot layer of semi-solid rock approximately 2,900 km thick and is composed mainly of ferro-magnesium silicates. This is where most of the internal heat of the Earth is located. Large convective cells in the mantle circulate heat and may drive plate tectonic processes.