A. You must have wronged me.
B. Oh! I’m so sorry about this.
C. Please stop just a second.
D. Are you Mr Smith
E. But may I ask you something first
F. Is there anything I can do for you
G. Now,sit down please.
A: Excuse me. (16)
B.Yes. You don’t know me,of course. I don’t teach here. I just give oral examinationshere now and then. Don’t be nervous.
A:Nervous Who Me
B: (17) I’m going to ask you a few questions. Then we are going to have a short con-versation in English. Do you understand
A:Yes,of course I do. (18)
B:After the examination,please. First of all,why are you learning English
A:Why am I learning English
B:Yes,I mean,what are you going to do with it Are you going to be a teacher of English, or what else
A: (19) I really must ask you something first.
B:Very well. If you insist,go ahead please!
A:Would you like a cup of coffee
B:Pardon What did you say
A:You see,I’m English. I’m one of the teachers here. I came to ask you if you would like a cup of coffee.
B: (20) .And thank you so much!

PGO回流产生故障的原因及处理？