Complex sentence: Upon the outbreak of the Anti-Japanese War in 1937, Li was appointed head of the Eighth Route Army offices in Shanghai, Nanking (Nanjing), and Guilin, the CCP Central Committee Yangtze Bureau Secretary, and as an assistant to Zhou Enlai.
Split into simpler sentences: Upon the outbreak of the Anti-Japanese War in 1937, Li was appointed head of the Eighth Route Army offices in Shanghai, Nanking (Nanjing), and Guilin. He also became the CCP Central Committee Yangtze Bureau Secretary, and an assistant to Zhou Enlai.