It left its tracks.
or
To the dock.
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Seven. One to change it and the other six to sing about how good the old one was.
or
Two. One to hold the bulb and the other to rotate the planet.
or
Well, first let's talk about the concept behind this whole "light bulb" thing.
or
A porcupine with split ends
or
In the neigh-borhood.
or