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If an abbreviation occurs at the end of sentence, is there one period or two? For example,

Caesar was assassinated in 44 B.C.. Brutus killed him.

Should there be one period or two?

This has nothing to do with etc.

marked as duplicate by FumbleFingers, Chenmunka, anongoodnurse, Mari-Lou A, Hellion Jun 7 '15 at 13:33

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  • 2
    Periods are heavy-duty punctuation; one period can do two jobs at once. – John Lawler Jun 4 '15 at 15:03
  • @John: and even three: My teacher said, "Caesar was assassinated in 44 B.C." – Peter Shor Jun 4 '15 at 15:14

Only one. Chicago manual of style covers this (with various examples). Other style guides will usually agree (they don't on everything). In your case BC is quite often used without punctuation anyway.

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