sentences:  On August 22, 1949, the communist I Corps took Linxia, completely annihilating Ma Bufang's nationalist Cavalry Army in the process.As the nationalist defenders of Lanzhou were threatened from rear and right flank, Ma Bufang was forced to withdraw the nationalist 8th Cavalry Division and the nationalist 14th Cavalry Division stationed in the northern bank of the Yellow River back to Xining to strength the defense of the provincial capital of Qinghai.The nationalist defense of Lanzhou was further weakened as a result.