Complex sentence: On 27 May 1949, the People's Liberation Army took control of Shanghai, which was one of only three former Republic of China (ROC) municipalities not merged into neighboring provinces over the next decade (the others being Beijing and Tianjin).
Split into simpler sentences: On 27 May 1949, the People's Liberation Army took control of Shanghai. Under the new People's Republic of China (PRC), Shanghai was one of only three municipalities not merged into neighboring provinces over the next decade (the others being Beijing and Tianjin).