A: None-there weren't any light bulbs in the 13th century.
Hella.
Hippies don't screw in light bulbs, they screw in tents.
Two. . . . . . . . . . . . . . . . . . . . . . . . . . IT JUST DOES, OKAY?
Only one but he has to have a nurse to tell him which end to screw in.
Ayatollah you already !