Knock knock. Who's there? Anita.

Anita who? Anita little help with these heavy bags!

Knock knock. Who's there? Brew.

Brew who? Tea-rific to meet you.

Knock knock. Who's there? Continue.

Continue who? Continue the joke. That's the whole thing. No pun.

Knock knock. Who's there? Fig.

Fig who? Fig-ure it out yourself, I'm busy!