单项选择题
A.0.1~10μg/cm2B.0.1~20μg/cm2C.0.1~30μg/cm2D.0.1~40μg/cm2
A.50~100μmB.70~100μmC.80~100μmD.90~100μm
A.NaClB.氰化钾C.Na2SO4D.NaHCO3