What parts are the internal structure of the earth divided into? Don't draw, just say it briefly.

1. Crust: divided into upper crust and lower crust. It is the sub-polar upper layer of the lithosphere.

2. Mantle: divided into upper mantle and lower mantle. The lithosphere is a part of it, above the asthenosphere. Most of the mantle exists in the form of fluid magma and other substances.

3. Earth core: divided into outer core and inner core. The outer nucleus is liquid, so it is also called the outer nucleus liquid sphere. The inner core is solid, mainly composed of iron and nickel, also called the inner core solid ring.