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Rainwater seeps into the ground and then rises to the surface in the form of a spring flowing down hills and mountains. As it is fed by more springs and meltwater from glaciers, it becomes a mountain stream, and then a young river. It continues flowing down the mountain, following steep slopes and forming waterfalls. The river carves out deep gorges, then broadens. Fed by tributaries, it becomes a large river. As it grows wider, the river forms meanders. Often, a delta forms at its mouth, saturated with the sediments that it has transported. Finally, it flows into the ocean. Water evaporation in the oceans forms clouds. The hydrologic cycle starts over.
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