补全对话。

A: Hello! 28361579.

B: Is 1              Mr. Jones?

A: Sorry, he 2              in at the moment. He left home a few minutes 3             .

B: 4              a pity! Will he come back soon?

A: I'm not sure. Can I 5              a message for him?

B: It's very 6              of you. There will 7              a meeting at 2:00 tomorrow afternoon.

    Please tell him to come 8              time.

A: I certainly will. I'll tell him as 9              as he comes back.

B: Thanks a lot. Good-bye!

A: You're 10             .

有苄基（C₆H₅CH₂—）.—OH.—CHO.—COOH四种基团，它们之间两两组合，所形成的有机物种类是

A．3

B．4

C．5

D．6