The Acid Test - Trains and Table Tennis Balls - ÃÛÑ¿´«Ã½ Sounds

The Acid Test - Trains and Table Tennis Balls - ÃÛÑ¿´«Ã½ Sounds
Trains and Table Tennis Balls
What do fast moving trains and table tennis balls have in common?
What do fast moving trains and table tennis balls have in common?