Because an undocumented worker has been living on his head for the past 2 decades!
or
None. They will never find one that burned as brightly as the first one.
or
proving once and for all that you can't have your kayak and heat it.
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It was in a jam!
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Only one, but she/he'll have to go out and buy the light bulb adaptor card first, which is extra.
or