5、I think I must go now.

4、It's time I was going, I'm afraid.

3、Oh, God, it's late, I've got to go.

2、It's five o'clock already. I must be off now.

　　　 A．Farewells:

1、It's getting late. I must be going.

2、It's my pleasure to have this chance to meet you.

1、How do you do? Pleased to meet you. (Glad to meet you. Nice to meet you.)

5、I'd like you to meet my friend Tom.

　　　　 B．Responses:

4、Please allow me to introduce my friend, Tom.

3、May I introduce myself? I'm Tom.