Blowing air into a whistle causes air to vibrate inside the whistle, and sounds are caused by vibrations in the air. Given these facts, what does blowing into a whistle do among the following options:
- makes a sight
 - makes sound
 - causes disruption
 - duplicate itself
 - unidirectional
 - decrease stamina
 - makes hearing
 - to move people


 

  makes sound       