Fact 1: Friction causes an object to lose energy.

Fact 2: Ultimately, frictional processes convert all of a wave's energy into heat.

Given the two facts above, answer the question "what is energy lost to?" with the following options: 
- heat
 - health
 - Bats
 - squids
 - living
 - life
 - cells
 - horses


 

 heat        