At one of the schools in London,the students can go into tow

At one of the schools in London,the students can go into town in the afternoon.But they must 51 to the school before six.One afternoon,Bob went to see a film.When he came back to the school,the school gate had already been closed.He went around the building to 52 door.That one was closed,too.Then he saw an open window on the 53 floor.It was the 54 office,Bob looked 55 the room,but no one was in.He quickly 56 into the room.Just then he heard a voice.Bob looked round and hid (躲藏) himself 57 a chair.Then the headteacher came in and sat down on the chair.He read a book for an hour.At last the headteacher stood up and went towards the door.“Thank goodness,he didn't 58 me.” Bob thought.59 he left the room,the headteacher spoke to the chair,“Would you please 60 the lights when you leave?” ( )51.A．come B．go C．return D．get ( )52.A．the other B．another C．small D．open ( )53.A．first B．second C．third D．fourth ( )54.A.teacher's B.headteacher's C.door keeper's D.students' ( )55.A．at B．out of C．into D．from ( )56.A．climbed B．went C．ran D．jumped ( )57.A．behind B．in front of C．beside D．under ( )58.A．see B．hear C．catch D．find ( )59.A．As soon as B．After C．Before D．When ( )60.A．turn up B．turn on C．turn down D．turn off