- Sonar usually is used for locating objects underwater
- Sonar is used to find the location of an object by sound waves
- So, sonar uses sound waves to locate objects underwater

Therefore, sonar uses sound waves to locate objects underwater
Q: Which of these uses sound waves to locate underwater objects?
Context:
- Sonar usually is used for locating objects underwater 
- Sonar is used to find the location of an object by sound waves