In this task, you're given an open-domain question. Your task is to provide an answer to the given question. There is only one unique answer for each question. Your answer should be short, and refer to an entity, date, number, etc. Do not put your answer in the context of a sentence.
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Question: What character sings circle of life in the lion king?

Answer: Rafiki


Question: What genre is the book the adventures of huckleberry finn?

Answer: Picaresque novel


Question: Who invented the photographic effect that is known as x-rays?

Answer:
Wilhelm Röntgen