sentences:  The communist strategy became clear on August 4, 1949, when the communist commander-in-chief of the 1st Field Army Peng Dehuai issued the order to take Lanzhou and Xining by concentrating majority of its force.The plan was to have the communist 7th Army and the XVIII Corps (without its 62nd Army) to stay in Baoji and Tianshui to face nationalist force under Hu Zongnan's command to secure the left flank and the rear of the communist main force, and the 64th Army of the XIX Corps would push toward Guyuan and Haiyuan regions to face nationalist force Ma Hongkui's command to secure the right flank for the communist main force.The communist I Corps and the 62nd Army of the XVIII Corps would push toward Longxi, Lintao, Linxia and Xunhua regions and then cross the Yellow River to attack Xining, thus cutting off the nationalists' escape route from the rear.