sentences:  The communist main force consisted of the II Corps and the XIX Corps without its 64th Army totaling 5 armies near 150,000 troops would push toward Lanzhou from Xi'an via Xi'an-Lanzhou highway in two fronts, the northern front and the southern front.On August 9, 1949, the communist 1st Field Army begun its attack toward Lanzhou and Xining from eastern Gansu.On August 14, 1949, the communist XIX Corps took Dingxi, while on August 16, 1949, the communist II Corps took Yuzhong and the communist I Corps took Lintao, forcing Ma Bufang's nationalist Cavalry Army to flee westward.