Fact 1: Cycles of freezing and thawing water cause ice wedging.

Fact 2: Ice wedging is the most important form of mechanical weathering.

Given the two facts above, answer the question "Cycles of freezing and thawing water cause " with the following options: 
- exposure to cold
 - the oak can fall
 - mechanical weathering
 - the looseness of soil
 - In the winter
 - Metling snow
 - colder and wetter
 - looseness of dirt or compost


 

   mechanical weathering      