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

Q: Which engineer built the Menai Suspension Bridge and the Caledonian Canal?

A: menai suspension bridge
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Q: Krist Novoselic and Dave Grohl were two thirds of which band, formed in Aberdeen (Washington State) whose albums include Bleach and In Utero?

A: dave grohl
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Q: What singer was backed by band known as Crazy Horse?

A:
crazy horse
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