Fact 1: Mammals conserve body heat with their hair or fur.

Fact 2: Mammals Hair or fur covers the bodies of most mammals.

Given the two facts above, answer the question "The protective covering on mammals, that helps them conserve body heat, is usually:" with the following options: 
- spiny
 - scaley
 - elastic
 - dense
 - fuzzy
 - skin
 - spiky
 - fat


 

     fuzzy    