补全对话。（A）
A: Can you tell me something about Egyptian pyramids?
B: Sure. There are many Egyptian pyramids in Egypt.
A:{#blank#}1{#/blank#}?
B:They were built around 2560 B.C.
A:{#blank#}2{#/blank#}?
B:The Great pyramid of Khufu. It is one of the "seven wonders"of the world. The ancient King Khufu ordered his men to build the Great Pyramid.
A: What was it made of?
B:{#blank#}3{#/blank#}.Each stone was fixed so well.
A:{#blank#}4{#/blank#}?
B: The biggest stone weighs as much as 15 tons.
A:{#blank#}5{#/blank#}?
B: To this day, it is still a mystery.
