Fact 1: Hydrogen bonds cause water to expand when it freezes.

Fact 2: Freezing water expands with tremendous force.

Given the two facts above, answer the question "Hydrogen bonds cause a tremendous force when a substance does what" with the following options: 
- strong
 - moves
 - harm
 - expelled
 - freezes
 - heat
 - breakdown
 - propagate


 

     freezes    