下列药物的碱性溶液加入铁氰化钾后，再加正丁醇，显蓝色荧光的是
A．维生素AB．维生素B1C．维生素CD．维生素DE．维生素E
参考答案：B
下面属有毒化学品标志的是[ ]
A.
B.
C.
D.
I don’t really work here; I ______ until the new secretary arrives.
A．just help out
B．have just helped out
C．am just helping out
D．will just help out
