Explanation:
1. War; Military intelligence. Poems of Yuefu, Songs of Liang Gujiao and Mulan Poems: "Wan Li went to Rongji and flew over the mountains." Tang Du Fu's poem "Sending Anger" said: "Since the emperor took over the throne, who will resume military service?" Song and Qin Guan's "Dai He,": "Entering Taiwan Province, waiting for the wind to break the threshold; Outside general managers are fighting for opportunities. Go to bed for mulberry. " Wang Shizhen in the Qing Dynasty, "I talk about the red north, talk about differences, Jingzhou mirror is unfair": "Many strange people, extended to the curtain. Every time there is a military opportunity, you must participate. "
2. Fighters; The timing of the battle. Ming Liuji's "Re-use Rhyme to Answer Master Yan": "Punish the people and protect the people, and the general will not lose the opportunity." Chapter 2 of Du Pengcheng's Defending Yan 'an: "The air force under your command must return at night to support Panlong Town. Don't miss the opportunity. "