题目

听下面一段独白, 回答以下小题。【1】Who stands in the middle of the three assistants?A.Mary. B.Gladys. C.Daniel.【2】What is Daniel in charge of?A.The computer lab.B.The reference department.C.The periodical area.【3】When is the library open on Fridays?A.From 8:00 am to 6:00 pm.B.From 9:00 am to 4:00 pm.C.From 9:00 am to 6:00 pm.【4】What will the assistants do next?A.Introduce the library. B.Ask some questions. C.Welcome the parents.下表所列各组物质中，物质之间通过一步反应就能实现如图所示转化的是 (　　)编号甲乙丙丁①CuCuOCuSO4Cu(NO3)2②Na2CO3NaOHNaHCO3CO2③N2NH3NONO2④CH3CH2BrC2H5OHCH2=CH2CH3CH3 A．①②③④      B．①②③      C．①③④      D．②③④