句子结构,定词从句mother took a long time in selecting a few hats for Mary ,out of which mary chose the one she liked best .请问which 前为什么用out of ,与哪个词搭配的

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out of 是与 a few hats 搭配的。也就是说妈妈花了很长时间来为玛丽从一些帽子中做选择，“从一些帽子中”，玛丽选择了她最喜欢的一个。