Three. One to climb the ladder while the second kicks the ladder out from under her. And the third to say, "I knew that was too high for you dear."
or
A sponge!
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Because he was feeling crumby.
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None, because people who glow in the dark don't need light bulbs.
Note: Topical to the Chernobyl Reactor disaster of 1984.
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Superman can fly, but a fly cannot superman!
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Lunch and dinner.
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