The document summarizes a trainee's practicum on explaining the interior of the Earth. The trainee explained to students that the interior of the Earth is made up of three layers - the crust, mantle, and core. The crust is the outermost layer up to 35 km deep made of silica and alumina. The mantle extends down 2,900 km below the crust and is made of silica and magnesium. The core is the innermost layer with a radius of 3,500 km made mostly of nickel and iron, and has very high temperature and pressure. The trainee concluded by reviewing the three layers and clarifying that the core has the highest temperature and pressure.