Combo photo shows a view of Bayi Town in Nyingchi, southwest China's Tibet Autonomous Region in the 1990s (up, taken by Chen Xie) and on July 20, 2021(bottom, taken by Purbu Zhaxi) respectively. On May 23, 1951, the Agreement of the Central People's Government and the Local Government of Tibet on Measures for the Peaceful Liberation of Tibet (17-Article Agreement) was signed, officially proclaiming the peaceful liberation of Tibet. The year 2021 marks the 70th anniversary of the historic event. (Xinhua)