The combination of uncontrollable natural conditions (earthquakes, heavy rainstorms, etc.) and artificially altered landforms can result in disastrous slope failures, and does.
(The combination of uncontrollable natural conditions; can result; in disastrous slope failures) (The combination of uncontrollable natural conditions; does; )
The combination of uncontrollable natural conditions The combination of uncontrollable natural conditions
can result does
in disastrous slope failures