I didn't know ____ I was supposed to do.[ ]
A. when
B. what
C. how
D. where
答案:B
购货交易正确截止是要求将12月31日前购入的存货,无论其是否已验收入库,都必须纳入存货盘点范围。( )
金属钾、钠等引起的火灾可用()扑救.(1)水(2)特殊干粉
A.1
B.2
C.1、2