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
Let's review. The Earth's mantle is the thickest layer of the planet and accounts for about 84% of the Earth's volume and 67% of its mass. It lies between the crust and the core. The Earth's mantle is never very far away from us; much closer than the Moon, for instance. But, it's truly an alien environment down there, a realm of extreme temperatures and pressures where rock undergoes convection like boiling water in a kettle.