Fact 1: Cold fronts cause thunderstorms as they pass by.

Fact 2: Fronts boundaries between air masses Fronts are boundaries between air masses .

Given the two facts above, answer the question "Boundaries between air masses can cause" with the following options: 
- Dehydration
 - friction
 - rain or sun shine
 - permineralization
 - heat energy
 - Pollution
 - Movement
 - thunderstorms


 

        thunderstorms 