これは特に膝を叩くほどのジョークではないので無理に笑う必要はありません。

Knock-knock.
　Who’s there?
Michael.
　Michael who?
Michael-esterol is high these days.

Knock-knock.
　Who’s there?
Ammonia.
　Ammonia who?
♫Ammonia side, oh, when times get rough.

Knock-knock.
　Who’s there?
Absent-minded.
　Absent-minded who?
I’m sorry, what?

Knock-knock.
　Who’s there?
Harmony.
　Harmony who?
Harmony more knock-knock jokes do we had to do here?