Blowing air into a whistle causes air to vibrate inside the whistle, and when an object moves or vibrates, the air molecules around the object also vibrate. Given these facts, blowing air into what causes air to move inside it among the following options:
- heat
 - solid plastic
 - solid glass
 - solid rock
 - whistle
 - sound
 - a chime
 - waves


 

     whistle    