Most canyons are formed by flowing rivers through erosion over long periods of time, and deep gorges and canyons formed by the river are tourist attractions. Given these facts, what are formed by flowing rivers through erosion over long periods of time among the following options:
- Sediment
 - soft soil
 - forests
 - deep gorges
 - cloud cover
 - patch reefs
 - big oceans
 - kalenchoes


 

    deep gorges     