托收项下的托收行和代收行()
A.负有审查单据的义务
B.只按委托人的指示办事
C.应保证收回相应的款项
D.一旦买方拒绝付款赎单,应代卖方提货报关
参考答案:B
在黄酮母核上引入7,4'-OH,可使黄酮类化合物
A.颜色加深
B.酸性增强
C.水溶性增加
D.稳定性增强
E.荧光增强
As nobody here knows what is wrong with the machine, we must send for an engineer to__________
the problem. [ ]
A. handle
B. raise
C. face
D. present