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

Fact 2: Erosion is loss of soil caused by rain and wind.

Given the two facts above, answer the question "Wind and rain cause what to become deeper and wider?" with the following options: 
- burrs
 - soil
 - time
 - effort
 - eroded
 - solutes
 - river
 - gaps


 

       river  