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

Q: The Battle of Antietam was fought during which war?

A: battle of antietam
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Q: Who has taken over the TV role of Doctor Who, from actor David Tennant?

A: doctor who
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Q: What bird is the symbol of Children's Penguin books ?

A:
penguin books
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