You are given a question. You need to detect which category better describes the question. A question belongs to the description category if it asks about description and abstract concepts. Entity questions are about entities such as animals, colors, sports, etc. Abbreviation questions ask about abbreviations and expressions abbreviated. Questions regarding human beings, description of a person, and a group or organization of persons are categorized as Human. Quantity questions are asking about numeric values and Location questions ask about locations, cities, and countries. Answer with "Description", "Entity", "Abbreviation", "Person", "Quantity", and "Location".
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Question: What 's the hardest substance in the human body ?

Answer: Entity


Question: How many home runs did Lou Gehrig have during his career ?

Answer: Quantity


Question: What 's the word for broken glass or sharp rocks embedded in cement on top of a wall ?

Answer:
Entity