1,000,001: One to change the bulb and 1,000,000 to rebuild civilization to the point where they need light bulbs again.
or
Thoreau editing Thorough.
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One's a spineless, poisonous blob. The other is a form of sea life.
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A snail because it carries it's home.
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Clerk: "Yes, sir. What size does your alligator wear?"
or