听力原文：M: You're going to wear out that typewriter.
W: Oh, hi. What are you doing here at this time of night？
M: I should ask you that question. Do you have any idea what time it is？
W: About ten or ten-thirty？
M: It's nearly midnight.
W: Really？ I didn't have any idea it was so late.
M: Don't you have an early class tomorrow morning？
W: Yes, at seven o' deck. My spare-time class, for students who go to work right after their lesson.
M: Then you ought to go to bed.
W: Ok.
When is the conversation taking place？

At ten.
B. At ten-thirty.
C. Nearly at mid-night.