Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

Q: What currency is used on Christmas Island?

A: christmas island
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Q: The song Don't Rain On My Parade features in which musical?

A: don't rain on my parade
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Q: Who wrote the 1968 novel '2001: A Space Odyssey'?

A:
2001: a space odyssey
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