_____ in the queue for half an hour, the old man suddenly realized he had left the cheque in the car.[ ]

A. Waiting

B. To wait

C. Having waited

D. To have waited

* * 新华门影壁上刻着的“为人民服务”表明了我国政府的宗旨，政府工作的基本原则是[ ]

A、人民民主专政

B、对人民负责

C、树立政府权威

D、接受人民监督