A、Doctor and nurse. B、Manager and secretary. C、Director and clerk. D、Professor and student. D

M: Er, could you please tell me how much this tie is?
W: Yes, of course. It’s 7 dollars, sir.
Q: If the man pays a 20-dollar note for two ties, how much will be the change?

W: What’s the deadline for the term paper, sir?
M: Since it should be no less then 10 type-written pages long, you can hand it in next week.
Q: What is the probable relationship between the two speakers?