根据所给图示完成对话。

A: What are you doing?

B: I'm    1    my plane. Thereis something wrong    2     it. Could you help me    3    it?

A: I'm    4   . I can't help you. I'm very busy now.

B: That's all right. Well,do you    5    a knife? Mine is at home.

A: Yes, I    6    one.

B: May I    7    it?

A: Certainly.    8    . Please give it back soon.

B: I think I can give it    9    to you this afternoon

A: This afternoon? I'm not at school.

B: What   10     tomorrow?

A: That's OK.

1.______ 2.______ 3.______ 4.______ 5.______

6.______ 7.______ 8.______ 9.______ 10.______

药物鉴别反应

维生素C

A．加酸产生白色沉淀 B．与硝酸银反应产生黑色沉淀
C．麦芽酚反应 D．硫色素反应
E．三氯化锑反应