Final answer:
Valleys, plains, and deltas are examples of landforms shaped by external geomorphic processes like erosion and water movement, as opposed to tectonic forces which create mountains.
Step-by-step explanation:
Landforms created by external geomorphic processes include features such as valleys, plain, and deltas. These landforms are typically shaped by forces such as erosion, weathering, and the movement of water. External geomorphic processes contrast with internal processes, such as tectonic forces, which create mountains and other upland features by the upthrusting of the Earth's crust. After mountains are formed, they may be sculpted further by external processes like ice erosion, leading to the characteristic sharp peaks and rugged landscapes we associate with mountain ranges.