完形填空。 At one of the school in London, the students can go into town in the afternoon. But they must 1 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 2 door. That one was closed, too. Then he saw an open window on the 3 floor. It was the 4 office, Bob looked 5 the room, but no one was in. He quickly 6 into the room. Just then he heard a voice. Bob looked round and hid (躲藏) himself 7 a chair. Then the head teacher came in and sat down on the chair. He read a book for an hour. At last the head teacher stood up and went towards the door. 'Thank goodness, he didn't 8 me.' Bob thought 9 he left the room, the head teacher spoke to the chair, 'Would you please 10 the lights when you leave?' (     )1. A. come (     )2. A. the other (     )3. A. first (     )4. A. teacher's (     )5. A. at (     )6  A. climbed (     )7. A. behind (     )8. A. see (     )9. A. As soon as (     )10. A. turn up B. go B. another B. second B. head teacher's B. out of B. went B. in front of B. hear B. After B. turn on C. return C. small C. third C. door keeper's C. into C.  ran C. beside C. catch C. Before C. turn down D. get D. open D. fourth D. students' D. from D. jumped D. under D. find D. When D. turn off