补全对话A:Hi,Dave.Do you know that the Great Wall is the longest wall of the world?
B:Yes.And I really admire your{#blank#}1{#/blank#}They were so clever and brave.
A:What do you think it was used for?
B:It might be used for keeping the wind from{#blank#}2{#/blank#}the sand away.
A:Oh,no.There used to be many wars in the north of China.So people built the Great Wall to prevent{#blank#}3{#/blank#} from entering China.
B:Oh,I see.Its{#blank#}4{#/blank#} was to protect people's safety,wasn't it?
A:Yes,you are right.At that time,the leader of China was Qing Shihuang.Thanks to the Great,he got {#blank#}5{#/blank#}of the wars and joined six countries into a big country.
B:He must be the greatest emperor in Chinese history.
A:No,he {#blank#}6{#/blank#} be the greatest one.In fact,the people lived a hard life at that time.
B:What was the Great Wall made {#blank#}7{#/blank#}?
A:Bricks and stones.Some of the stones are so huge that they {#blank#}8{#/blank#} as much as two tons.
B:Really?I wonder how they managed to move and{#blank#}9{#/blank#}up those heavy stones without modern machines.
A:Yes,there remain many{#blank#}10{#/blank#} about it waiting for us to discover.
