Knock Knock.
Who's there?
Europe.
Europe who?
No, YOU'RE a pooh.
Knock knock. Who?s there?
Spell.
Spell who?
double you aich oh
Knock knock. Who?s there?
Tank.
Tank who?
You?re welcome!
Knock, knock.
Who's there?
Wooden shoe.
Wooden shoe, who?
Wooden shoe like to know!