Fact 1: Temperature falls from lower to higher altitudes.

Fact 2: Temperatures are cooler in the higher altitudes of the mountains.

Given the two facts above, answer the question "Temperature falls from lower to higher where?" with the following options: 
- space
 - burning coal
 - underground
 - mountains
 - frontal zones
 - the ground
 - deserts
 - burrows


 

    mountains     