Colorful balloons fly into the sky at a grand ceremony marking the 50th anniversary of the founding of the Tibet Autonomous Region at the square of the Potala Palace in Lhasa, capital of southwest China's Tibet Autonomous Region, Sept. 8, 2015. (Xinhua/Chogo)

　　Colorful balloons fly into the sky at a grand ceremony marking the 50th anniversary of the founding of the Tibet Autonomous Region at the square of the Potala Palace in Lhasa, capital of southwest China's Tibet Autonomous Region, Sept. 8, 2015. (Xinhua/Purbu Zhaxi)

　　Colorful balloons fly into the sky at a grand ceremony marking the 50th anniversary of the founding of the Tibet Autonomous Region at the square of the Potala Palace in Lhasa, capital of southwest China's Tibet Autonomous Region, Sept. 8, 2015. (Xinhua/Chogo)