Knock-knock!
Who's there?
Boo
Boo who?
Don't cry, it's only a joke!

Knock-knock!
Who's there?
Tank
Tank who?
You're welcome!

Knock-knock!
Who's there?
Ada
Ada who?
Ada salad for lunch!

Knock-knock!
Who's there?
Emma
Emma who?
Emma bit cold out here, will you let me in?

Knock-knock!
Who's there?
Duey
Duey who?
Duey have to keep telling Knock-knock jokes?