Fact 1: Sonar is used to find the location of an object.

Fact 2: Sonar devices use sound waves to find things.

Given the two facts above, answer the question "what are used to find the location of an object?" with the following options: 
- A Greek letter
 - satellites
 - electricity
 - rays or beams
 - Firecrackers
 - photons
 - sound waves
 - microscope


 

       sound waves  