the north of Su Ping gave a loud drink, like a thunderbolt on the flat ground, reverberating in the canyon.,all Qin troops immediately began to act in accordance with the predetermined battle plan.,the soldiers ambushed on the edge of the cliff riveted hard and pushed the prepared boulders around them off the cliff. When the stones were finished, they took out the tung oil they carried with them. Each soldier could not carry much tung oil, that is, the quantity of three kettles, but it could not hold a large number of people.。