请选择一个正确答案,完成(37)处的填空。

请选择一个正确答案,完成(37)处的填空。

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During the trial period, the customer pays a reduced amount

During the trial period, the customer pays a reduced amount to rent the machine.

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下列哪项不符合病例对照研究的定义和内涵

下列哪项不符合病例对照研究的定义和内涵

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