At Harton College--an English boarding school for boys--there are many rules. 15-year-old Bob Sanders often breaks them. The boys can go into the town in the afternoon after class. But they must return to the school at six o'clock. One afternoon Bob walked to the town. He looked at the shops and then went to the cinema. When the film was over, it was after eight o'clock. He was a little worried. He walked back to prefix = st1 /HartonCollegeas fast as possible. When he arrived, he ran quickly to the main entrance. It was locked. He went round the school . uilding to another door, which was locked, too. He looked up at the window of his dormitory on the third floor. The window was open, but it was quite dark and he could not climb up the wall easily. Then he saw another open window on the ground floor. It was the window of the headmaster's study. He looked into the room--no one was there. Bob quickly climbed onto the window sill and jumped into the room. Just then he heard a noise. Then someone turned on a light in the corridor. Bob looked around and then hid under the sofa. One minute later, Mr. Mannering, the headmaster, came in. He turned on the light on his desk, and sat down on the sofa. Then he opened a book and began to read. Bob lay under the sofa as quietly as possible. He couldn't move. The floor was cold and uncomfortable. He looked at the headmaster's shoes and socks for an hour. "Why doesn't he get up and go to bed?" Bob thought. Mr. Mannering read his book for another hour. Finally, the headmaster closed his book and stood up. He put the book on a shelf and walked towards the door. "Thank heavens he didn't find me under the sofa," thought Bob. Then Mr. Mannering stopped and spoke towards the sofa. "Would you turn off the light when you leave?" He said, and left the study. It can be inferred that Mr. Mannering     .
knew that Bob was still at the cinema knew that Bob was in the dormitory knew exactly where Bob was didn't know clearly where Bob was