Zheng Tongbei went to visit Wang Zhao. Wang Zhao said, "You are a learned man in the south. What do you think of coming here? " Zheng Tong replied, "I am a humble and ignorant southerner. Is there anything worth asking me? " . Of course, in spite of this, your majesty, you still put the question in front of me. How dare I not answer it? When I was young, my father taught me the art of war. "Wang Zhao said," I don't like the art of war. Hearing this, Zheng Tong clapped his hands and laughed. He said: "Sun Tzu's art of war is the most cunning thing in the world. I thought you didn't like it. I used Sun Tzu's Art of War to talk about King Zhao of Wei, and Zhao Haoqi also said,' I don't like it.' I said,' Can your majesty's behavior be compared with Xu You? Not bound by worldly fame and fortune, he did not accept Yao's death. But now that your majesty has accepted the land left by his predecessor, is it necessary to make the souls of ancestors safe, the territory of the country will not be violated, and the gods of the country will not be sacrificed? "King Zhao of Wei said," of course. I said, now, if someone is camping in the wild alone with Hou's pearls, beautiful jade produced in autumn, and millions of dollars, it is not as decisive as Meng Benwei, and there is no strong bow and arrow around to protect themselves, then they will be killed in less than one night. Now there are powerful and greedy countries approaching the king's border and claiming territory from him. They won't listen to them. In this case, if you don't have a country's defense equipment in the war, what will you use to resist them? Your majesty, if you don't stress the strategy of using force, then the ambitions of neighboring countries will succeed. Zhao Wang said, "I ask you to give me more advice. "