In this combo photo, the upper part taken by Ren Yongzhao shows residents buying tea kettles in Lhasa in the 1950s; and the lower part taken by Purbu Zhaxi on Dec. 12, 2011 shows a villager using a blender to make butter tea for her family in Xigaze, southwest China's Tibet Autonomous Region. 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)
