若要在紫外光区测定样品，应选用的光源是______。
   A．氘灯    B．钨灯    C．汞灯    D．空心阴极灯

The ' straight-line ' method of depreciation______.A．allows an equal amount to be charged as depreciation for each year of the expected use of the assetB．is computed by dividing the adjusted basis of a property by the estimated number of years of remaining useful lifeC．assumes that the depreciation of an asset is a uniform. function of timeD．all of the above 点击查看答案

离子选择性电极的膜电位是由于______而产生的。 A．离子在电极敏感膜上迁移和交换B．电子转移 C．电极与溶液之间的电荷转移 D．溶液中的离子交换

A.离子在电极敏感膜上迁移和交换B．电子转移

B.电极与溶液之间的电荷转移

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