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

Fact 2: Building insulation is a cellulose material made of ground computer paper and cardboard boxes.

Given the two facts above, answer the question "What can keep a home warm?" with the following options: 
- cellulose material
 - an electric stove
 - Movement of an air mass
 - plastic wrap
 - water
 - bubble tape
 - electricity
 - Animal fur


 

 cellulose material        