Fact 1: Thick fur can be used for keeping warm.

Fact 2: Sheep are mammals with thick, woolly fur, and hoofed feet.

Given the two facts above, answer the question "sheep have what fur to keep warm" with the following options: 
- cropped
 - wooly
 - fats
 - white
 - straight
 - hair
 - warmth
 - warm


 

  wooly       