Where Do Mountains Come from?

There are many mountains on the earth. Some are high and some are low. Some are ranges a few hundred or even a few thousand kilometres long, and some are solitary mountains. Mountains all come from the earth. A long, long time ago, the surface of the earth was not as solid and stable as it is now and on the earth there were a few big continents separated from each other. As the bumped against each other, some earth surfaces grew higher and higher. As the years went by, they grew into today's mountains. There are also mountains that are formed out of volcanic eruptions.