密度是指在一定条件下,()与测定平均值相符合的程度。
A.多次测定结果平均值
B.检出限
C.每次的测量值
D.真值
E.测定最大值
F.测定最小值
(G)测定极差值
参考答案:C, G
香豆素可与三氯化铁试剂反应呈蓝绿色,是因为其具有
A.酚羟基B.内酯环结构C.1745~1715cm-1D.甲氧基E.3600~3200cm-1
The man went to bed, and when he woke up,he found his shoes still on.
A.having drunk
B.being drunk
C.drinking
D.drunk