You are presented with the question "Mammals keep what with hair or fur?" and the following answer choices: 
- coat
 - wool
 - energy
 - nektar
 - warm
 - cold
 - shivering
 - hydrated

Now knowing that mammals conserve body heat with their hair or fur and birds waste a lot of body heat trying to keep warm in exposed areas, choose the best answer.


 

     warm    