Fact 1: Erosion causes a river to become deeper and wider.

Fact 2: Canyon formed as a consequence of river erosion.

Given the two facts above, answer the question "What are formed by erosion?" with the following options: 
- mountains
 - hills
 - canyons
 - Sediment
 - loose soil
 - rocks
 - soils
 - streams


 

   canyons      