In the four layers of the earth, which two are liquid?
The two layers of the earth that are liquid include the outer core and the mantle. The outer core is less viscous than the mantle. The inner core, which is the innermost layer, is a solid section which is unattached to the mantle. It is always suspended by the molten outer core. Learn more from http://library.thinkquest.org/28327/main/universe/solar_system/planets/earth/interior/layers_of_earth.html.