A crane.
or
Elvis Parsley.
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It takes two to tangle!
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They turn from notating nuclear spins to notating unclear puns.
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Executive Producers don't screw in a light bulb, they screw in a hot tub.
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Twenty. One to hold the bulb, two to turn the ladder, and 17 to be on the guest list.
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The baker, because he has lots of dough.
or