Fact 1: Soil is formed by rocks eroding.

Fact 2: Soils are formed by breakdown of rock.

Given the two facts above, answer the question "what does rock erosion cause them to do?" with the following options: 
- turn gaseous
 - secrete h2o
 - breakdown
 - become hydrogen
 - they bend
 - dangerous
 - migrate
 - watershred


 

   breakdown      