The sun is the ultimate source of energy for life systems while heat convection currents deep within the earth are an energy source for gradually shaping the earth's surface.
(The sun; is; the ultimate source of energy for life systems) (heat convection currents deep within the earth; are; an energy source for gradually shaping the earth's surface)
The sun heat convection currents deep within the earth
is are
the ultimate source of energy for life systems
an energy source for gradually shaping the earth's surface