C193 Golden Essence

"Hoo hoo!" Yang Ao panted heavily. After digging for three hours, he was covered in sweat. He was even more tired than digging for so long. The deeper he dug, the greater the density of gold. The digging speed would also slow down, and all the spades of the robot would be broken.

"Reporting, sir. The tools have all been destroyed and cannot be excavated