The barman says, "Is this some kind of joke?"
or
Because everything else on the plate is crackers.
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Silly, WASPs don't screw in a light bulb, they screw in a hot tub.
or
CoFe2
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The neutron says "Are you sure?" The proton replies "I'm positive."
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One. No, two. No... How many do we have on the truck?
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and then it dawned on me.
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Uh...standby, I'll check on that.
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Fifty — one to screw in the bulb and 49 to guard him/her.
or