Answer:
They are called simple machines because they don't need too much tools to be build
A. Representative Democracy.
There are 6 layers of earth. The inner and outer core, upper and lower mantle, and continental and oceanic crust. The crust and the inner core are solid, whereas the outer core and inner mantle are liquid. The outer mantle is semi solid.
<span>Caucasus Zagros Lena Ural</span>
