You are presented with the question "periscopes are used to find out what about objects" and the following answer choices: 
- microscopic
 - density
 - location
 - weight
 - Light
 - energy
 - observe it
 - age

Now knowing that sonar is used to find the location of an object and periscopes are still useful, despite the sonar and electronic sensors of modern submarines, choose the best answer.


 

   location      