Fact 1: Insulated material can be used for keeping warm.

Fact 2: Insulators are materials that prevent the flow of heat.

Given the two facts above, answer the question "Materials that prevent the flow of heat can be used for keeping what?" with the following options: 
- airy
 - power
 - warm
 - liquid
 - dry
 - energy
 - empty
 - down


 

   warm      