A、30 minutes. B、20 minutes. C、1 hour. D、40 minutes. B

W: Jim, thank goodness, you’ve arrived, the class presentation started half an hour ago and I was really desperate.
M: I am terribly sorry that I’m late, Jane, This morning has been a real mess, I didn’t think I could mange to be here.
W: Why are you late? You know, the graphs you are holding are very important for our presentation.
M: Yes, I know, I’ll tell you about it later. Ok, let’s see how we are doing on time. Two groups are still ahead of us, aren’t they? That means we’ve got about twenty minutes to prepare for our presentation on the rights of the consumers and the analysis of the stock market...
W: You do look cold. What happened to you?
M: I’ve been standing outside in the cold weather for over an hour waiting for a bus.
W: Over an hour? But your apartment was only a ten-minute bus ride to our campus.
M: On normal conditions, but the bus was delayed because of the weather and when I stepped into a drugstore to call home for a ride, the bus went by. But there was no one at home, I had to wait another forty five minutes for the next bus.
W: Er ... you are really unlucky today. Well, we still get twenty minutes to gather our wits together.
M: We’d better stop chatting; People are turning around and looking at us.