The pianist waited for silence ____ he began to play.
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They promised to wait ____ the clock struck twelve.
He looked pale ____ he had seen a ghost.
地西泮溶于硫酸后,在紫外灯下呈现()
A. 黄绿色荧光
B. 紫色色荧光
C. 蓝色荧光
D. 黄色荧光
( )系指样品中被测物能被定量测定的最低量,其测定结果应符合准确度和精密度要求。
A. 定量限
B. 检测限
C. LOD
D. LOQ
E. 检出限