One's a spineless, poisonous blob. The other is a form of sea life.
or
None: they just deny that the bulb ever went out in the first place.
or
He wanted to win the no-bell prize!
or
Because there are too many ears.
or
Two, one to call the electrician, and one to mix the drinks.
or
100: One to do it and ninety-nine to say "I could've done that."
or