Fact 1: Soil is formed by rocks eroding.

Fact 2: Rivers erode the rocks they flow over.

Given the two facts above, answer the question "What do rivers do to rocks?" with the following options: 
- storing water
 - to move people
 - they bend
 - Make them get bigger
 - It has no effect on rocks
 - Polish them
 - Turn it to soil
 - protect them


 

       Turn it to soil  