Heating of the ocean water by the sun is the key process that keeps the hydrologic cycle in motion.
(Heating of the ocean water by the sun; is; the key process that keeps the hydrologic cycle in motion) (the key process; keeps; the hydrologic cycle; in motion)
Heating of the ocean water by the sun the key process
is keeps
the key process that keeps the hydrologic cycle in motion
the hydrologic cycle in motion