对乙酰氨基酚的含量测定方法有()
A.亚硝酸钠滴定法
B.双相滴定法
C.高效液相色谱法
D.紫外分光光度法
E.非水溶液滴定法
参考答案:A, C, D
向下列溶液中各加入少量Ba(OH)2固体,溶液的导电能力变化最大的是( )
A.盐酸
B.Na2SO4溶液
C.硫酸
D.MgCl2溶液
With his mind________, he didn't catch even a single word of what the teacher was saying. [ ]
A. wondering
B. wandering
C. drifting
D. floating