A：It's getting dark.
B：Yes, what time is it? I don't have my watch with me.
A：It's ten minutes to five.
B：Perhaps your watch is slow.
A：Oh, it has stopped. I must have forgotten to wind it last night.
B：Let's ask Mary over there. Mary, have you got the time?
C：Yes, it's six twenty.
B：Is your watch right?
C：I think so. I set it by the radio this morning.