Fact 1: Aradio converts electrical energy into vibrations.

Fact 2: Electric energy is stored in batteries.

Given the two facts above, answer the question "What does a radio use to make vibrations?" with the following options: 
- waves
 - rays or beams
 - a battery
 - an object
 - barrel-shaped
 - nerves
 - Loud noises
 - it needs them


 

   a battery      