题目

Tom arrived at the bus station quite early for the London bus. The bus for London would not leave until five to twelve. He saw a lot of people waiting in the station. Some were standing in lines, others were walking about. There was a group of school-girls. Their teacher was trying to keep them in order. Tom looked around but there was nowhere for him to sit.He walked into the station cafe. He looked up at the clock there. It was only twenty to twelve. He found a seat and sat down, facing a large mirror(镜子) on the wall. Just then, John, one of Tom’s friends, came in and sat with Tom.“W云南到广西的一条重要铁路是 [     ]A、滇藏线 B、南昆线 C、成昆线 D、贵昆线