Fact 1: When an animal moves , chemical energy is converted to mechanical energy.

Fact 2: Cows are social animals.

Given the two facts above, answer the question "what converts chemical energy to mechanical energy when it moves?" with the following options: 
- Birds
 - bears
 - cows
 - Whales
 - toads
 - hawks
 - cars
 - fish


 

   cows      