Knock Knock!
Who's there?
Cow-go
Cow-go Who?
No, Cow go MOO!!!
Knock Knock!
Who's there?
I used.
I used who?
I used to be able to reach the doorbell, but now I can't!
Knock Knock!
Who's there?
Vitamin.
Vitamin who?
Vitamin in for a party!
Knock Knock!
Who's there?
Get off.
Get off who?
Get off the Internet!