Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.
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Question: the mysteries of alfred hedgehog is a tv show made in france and canada.

Answer: the mysteries of alfred hedgehog


Question: tatsuya kamohara (born 8 july 1983) is a japanese football player.

Answer: tatsuya kamohara


Question: in physics, a gravitational field is a model used to explain the influence that a massive body has.

Answer:
gravitational field