B. Political basis: During the Warring States period, big countries merged with small countries, leading to partial reunification.
C. popular will: after a long period of war, the people hate war and long for reunification.
D. Material foundation: Qin is rich and powerful, and its strength exceeds that of other countries.
Theoretical basis: Han Feizi's legalist thought.
② Subjective conditions: Ying Zheng, King of Qin, is wise: a. Appoint foreign talents.
B, the correct strategy and tactics (inbreeding far attack)
2. The process of reunification: ① Destroy the Six Kingdoms (time: 230 years ago -22 1 year ago) → Zhao Han Wei early Yan Qi.
(2) Pingyao people set up three counties to strengthen the control of the southwest (Lingqu: connecting the two major water systems of the Yangtze River and the Pearl River, it is one of the oldest artificial canals in the world)
③ Strike Xiongnu: Take Hetao area and build the Great Wall of Wan Li. Continue to ask: What measures did the Qin Dynasty take to strengthen its rule? What was the reason for unifying the currency in Qin Dynasty? What is the standard? Supplementary answer: (1) Measures to strengthen centralization in the Qin Dynasty: 1) Politically establish the supremacy of imperial power, and set up central and local administrative agencies (the central government has a prime minister, imperial envoys, and Qiu; The county system is implemented locally) 2) Economically, unified measurement, currency and train tracks; 3) Culturally, unified writing; 4) Ideologically, burning books pits Confucianism.