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

Q: In which city was Christopher Columbus born?

A: columbus
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Q: Which Bob Dylan song begins You got a lotta nerveTo say you are my friend. When I was down, You just stood there grinning?

A: bob dylan
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Q: What is the name of 'Bob the Builder's' cement mixer?

A:
bob the builder
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