It ran out of juice!
or
Because it goes good with chips.
or
None, because they were copycats
or
A bad lawyer makes your case drag on for years. A good lawyer makes it last even longer.
or
A mushroom!
or
None. They will never find a bulb that burns as brightly as the old one.
or
Two, one to call the electrician, and one to mix the drinks.
or