Fact 1: If gas is heated then that gas will expand.

Fact 2: Cottages are heated by gas space heat or gas furnaces.

Given the two facts above, answer the question "gas does what after going through a furnace into a cottage" with the following options: 
- expands
 - becomes toxic
 - has odor
 - warmth
 - Rise
 - moves
 - burning
 - compresses


 

 expands        