A：Look, Tom!____.

B：I'm sorry I forget its name, but I know something about it.

A：____

B：It was invented seven hundred years ago.

A：____

B：A Chinese scientist, Zhang He.

A：____

B：No, it wasn't. It was used for testing earthquakes.

A：How clever people in ancient China were!

B：You're right. Inventions have changed our life greatly.____

A：I want to invent a time machine.

B：That sounds great!

A. Who invented it?

B. Where was it made?

C. What's that over there?

D. When was it invented?

E. What do you want to invent?

F. Was it used for holding water?

G. What do you think is the most useful invention in the world?