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If the surface of the earth is always eroding away, why hasn't it eroded away completely by now?
a) Not enough time has passed for it to erode away,
b) Eroded Earth materials are deposited somewhere else.
c) Earthquakes and volcanoes create new hills and mountains.
d) People change the Earth's surface as they build cities and towns.
What is Earthquakes and volcanoes create new hills and mountains?