Just one, but he'll also want to do something about your nose.
or
If one side has one, the other side has to get one. Once launched, they cannot be recalled. When they land, they screw up everything forever.
or
A garbage truck.
or
Because she wanted to get a good scoop.
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Holes.
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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.
or
She was the fairest in the land.
or