Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
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Question: In music, which band consists of Billy Gibbons, Dusty Hill and Frank Beard?

Answer: frank beard

Question: Although it was headquartered at Oak Ridge, TN, and the University of Chicago, what was the name of the WWII project that created the atomic bomb?

Answer: nuclear weapon

Question: Who played Frank Spencer's long suffering wife Betty in the TV series Some Mothers Do 'Ave 'Em?

Answer:
some mothers do 'ave 'em