Given an trivia question precisely answer the question with a word/phrase/name. External resources such as Wikipedia could be used to obtain the facts.
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Question: What was the 1910 Fruitgum Company's only hit?

Answer: simon says


Question: What, in 1985, was Madonna's first UK No. 1?

Answer: into the groove


Question: What waltz by Johann Strauss II was named after a European river?

Answer:
the blue danube