Contrary to popular belief, the first ironclad warships were built by Korea in the 16th century.
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Approximately 40% of the U.S. paper currency in circulation was counterfeit by the end of the Civil War.
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There are 92 known cases of nuclear bombs lost at sea.
148
The exact cause of death and burial site of Genghis Khan is unknown, because all of the 2000 funeral guests and 800 soldiers were killed in order to preserve the secret.
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No one knows who designed the first American Flag.
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Tickling was a form of torture used in ancient China on nobility because it left no mark and recovery was quick.
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