Fact 1: Breaking apart rocks can cause debris.

Fact 2: Erosion is the breaking apart and moving of rocks and soil.

Given the two facts above, answer the question "What can break rocks and cause debris?" with the following options: 
- sand
 - trees
 - erosion
 - wind
 - Surf
 - Earthworms
 - flooding
 - rivers


 

   erosion      