Fact 1: Soil is formed by weathering.

Fact 2: Soil or dirt is a very heavy material.

Given the two facts above, answer the question "a very heavy material is formed by what?" with the following options: 
- eating
 - weathering
 - Condensation
 - rainfall
 - calcite
 - seeding
 - burning
 - sanding


 

  weathering       