下列有关维生素D的叙述，哪项是错误的（　　）

下列有关维生素D的叙述，哪项是错误的（　　）A．维生素D的活性形式是1，25-（OH）2-D3 B．维生素D的两次羟化作用都是在肝中进行 C．促进小肠中钙结合蛋

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在水利水电工程注册建造师执业工程规模标准中，农村饮水工程的执业工程规模标准根据其（　　）确定。

在水利水电工程注册建造师执业工程规模标准中，农村饮水工程的执业工程规模标准根据其（　　）确定。A．等别 B．级别 C．投资额 D．供水人口数量

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How can a teacher acquire infinite patience?75

How can a teacher acquire infinite patience?75

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Executives of the company enjoyed an ________ lifestyle of f

Executives of the company enjoyed an ________ lifestyle of free gifts, fine wine

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It is reported that thirty people were killed in a ________

It is reported that thirty people were killed in a ________ on the railway yeste

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