A:Excuse me . I've been waiting here for 15 mins . Do you know how often does No . 3 run ? B: Oh , it runs <MASK> . You must have missed it , when you came here . It should be here any minute now . A: It seems that you have got here at a good time . Do you have a bus schedule ? B: Yes , I do . You can go to the Transport Department to get yourself a bus schedule and a bus route map . A: I see , thank you .
every 20 mins Every five hours Every two seconds