A: What's that?
B:
A: When was it invented?
B:
A: How did it work?
B:They pushed the pedals down hard with their feet.
A: What was it made of?
B: It was made of wood.
A. It can hardly be seen in China now.
B. It was invented many years ago.
C. Usually two people stood on it.
D. It was used for getting water.
E. Then the water could be brought up.
F. It's an old machine.
G. What was it used for?