下列哪种方法可以测定维生素A（）。A.三氯化锑比色法 B.2，4-二硝基苯肼比色法

 54是（   ）位数，十位上的数5表示（   ）个（   ），个位上的数4表示（   ）个（   ）。

________ really enjoyable, ____________ us a valuable lesson.

A．Not only the film was; but also it gave

B．Not only was the film; but also it gave

C．Not only the film was; but did it also give

D．Not only was the film; but did it also give

主厂房内吊车轨顶高程是如何确定的？

取皮肤癣症皮屑处理后镜下鉴别真菌主要观察的是（）

A.芽胞

B.菌丝与孢子

C.假菌丝

D.荚膜

E.细胞壁结构

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