The central portion of Earth below the mantle, beginning at a depth of about2, 900 kilometers(1, 800 miles) and probably consisting of iron and nickel. It is made up of a liquid outer core and a solid inner core.是什么意思_The central portion of Earth below the mantle, beginning at a depth of about2, 900 kilometers(1, 800 miles) and probably consisting of iron and nickel. It is made up of a liquid outer core and a solid inner core.在线翻译_英语_读音_用法_例句