Introduction to the fourth part: The fourth exhibition hall displays historical materials, documents and pictures of the Second Division of the New Fourth Army and the Huainan Anti-Japanese Base Area, the Fourth Division of the New Fourth Army and the Huaibei Anti-Japanese Base Area, persisting in the war of resistance behind enemy lines, and consolidating and expanding the Huainan and Huaibei Anti-Japanese Base Areas. The fifth exhibition hall shows how the Fifth Division of the New Fourth Army and the Hubei-Henan border anti-Japanese base areas persisted in the war of resistance to complete the siege of Wuhan under unprecedented severe Japanese and puppet army attacks and natural disasters, actively carried out local counterattacks, and cooperated with the Eighth Route Army's southward development of the Hubei-Henan border and Anhui provinces. , Hunan, Jiangxi, as well as the Seventh Division of the New Fourth Army and the Wanjiang Anti-Japanese Base Area to persist in the struggle, and consolidate and develop historical materials and weapons from the Anti-Japanese Base Area.