—_______ Sunday morning, they are going to get up early .

—That’s good , but I’m going to stay in bed _________ the morning .

A．On , on

B．In, in

C．In , on

D．On, in

氢氧化钡可使强心苷中下列哪些部位的酯键水解脱去酰基（）

A.α-去氧糖上的酯键

B.α-羟基糖上的酯键

C.苷元上的酯键

D.苷元内酯环开裂

E.D-葡萄糖上的酯键