根据对话内容，从方框内选择合适的句子补全对话。(有两项多余) A. It can hardly be seen in China now. B. Then the water could be brought up. C. It was invented many years ago. D. Usually two people stood on it. E. It was used for getting water. F. It's an old machine. G. What was it used for? A: What's that? B: (1)_________ A: When was it invented? B: (2)_________ A: How did it work? B: (3)_________ They pushed the pedals (踏板) down hard with their feet. (4)_________ A: What was it made of? B: It was made of wood. (5)_________ A: Yes, I never saw such a machine before.