You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.
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Question: Category: CROSSWORD CLUES "D _ _ _ ER" 
Clue: Macbeth thought he saw one

Answer: a dagger


Question: Category: ONE-WORD BEST PICTURE OSCAR WINNERS 
Clue: A middle name in Latin

Answer: amadeus


Question: Category: DISCOVERIES & INVENTIONS 
Clue: Robert Watson-Watt's development of this use for radio waves in 1935 helped win the Battle of Britain

Answer:
radar