根据课文内容,补全对话。
Simon: How long is the Great Wall?
Daming: It's more than __________ thousand li long.
Simon: __________ thousand li?
Daming: Yes. That's more than __________ thousand kilometres!
Simon: Wow! That's __________ long! How old is it?
Daming: It's more than __________ __________ years old.
Simon: Oh, that's very old. Can you tell me __________ __________ the Great Wall?
Daming: __________ __________.