药物与鉴别反应
与硝酸银生成黑色沉淀
A．维生素K1B．维生素B1C．维生素B2D．维生素CE．维生素E
参考答案：D
—Whose notebook is this?
—It _____ Jane's. It has her name on it. [ ]
A. must be
B. might belong to
C. may be
D. could be
世界上公认的第1台电子计算机诞生的年份是
A．1943
B．1946
C．1950
D．1951
