—How long have you known the doctor ?

—          he helped me three years ago.

A. When　        B. Before　         C. Because      D. Since

---How long have you known the doctor ?  

---_________he helped me three years ago.

A. When　           B. Before　          C. Because             D. Since

在横线上填入词或句子，将对话补充完整.(　５分　)　

Ａ: Hello, Nice to meet you!

B: ___1.____! How long have you been in Zhuzhou?

A: For half a year.

B: ___2.__?

A: It is a beautiful city.

B: Why did you come to study here?

A: Because my father got a job here.

B: Oh, __3.___?

A: He is a policeman.

B: Cool, I want to be a policeman, too.___ 4.____?

A: I want to be a singer.

B: ___5.__?

A: Because I like singing very much.

仔细阅读对话，选择恰当的答语。