Yang Qi brought Yan Fei a surprise. He had used a pile of completely worthless discarded rocks to create an incredibly hard cement product. Pointing at those rocks, Yang Qi said, "Yan Fei, you might not be aware and think these rocks are just ordinary, useless stones that you've casually thrown away. But I'm telling you, they're not ordinary, they're Super Rocks with special uses."
Yan Fei asked, "Super Rock? Why do you use 'super' to describe it? Is it because of its hardness?"
Yang Qi replied, "Hardness is only one aspect of it. The reason I call it Super Rock is because of another unique physical property it possesses."
Filled with curiosity, Yan Fei asked, "What physical property?"
