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.

Q: Category: "Y"? 
Clue: You can split the atom or even do barrel rolls using this toy

A: a yo-yo
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Q: Category: "OVER" & "OUT" 
Clue: The remote part of Australia

A: the outback
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Q: Category: NATURE 
Clue: Mor & mull are 2 types of this black decayed organic matter in soil

A:
humus
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