M: Excuse me. Have you been waiting long? W: Twenty minutes already. M: Did you notice whether the No. 7 bus has passed by? W: Not while I've been standing here. I'm also waiting for the No. 7 bus myself. M: Good. Hot today, isn't it? W: Yes, it is. I wish that it would rain and cool off. M: Me, too. This is unusual for March. I don't remember it ever being so hot and dry in March before. W: My mother and I have just moved here from Indiana. It is pretty cold there. M: Yes, I've heard of that. W: Do you think we've missed the has? M: Take it easy. It never comes exactly on the half hour like it should., Question: How often should the bus come to their stop? (A) Every twenty minutes. (B) Every half an hour. (C) Once a day.
(B) Every half an hour.