Gulls fly over the Lhasa River in Lhasa, capital of southwest China's Tibet Autonomous Region, Nov. 25, 2012. [Xinhua]

Gulls fly over the Lhasa River in Lhasa, capital of southwest China's Tibet Autonomous Region, Nov. 25, 2012. [Xinhua]

Gulls fly over the Lhasa River in Lhasa, capital of southwest China's Tibet Autonomous Region, Nov. 25, 2012. [Xinhua]

Gulls fly over the Lhasa River in Lhasa, capital of southwest China's Tibet Autonomous Region, Nov. 25, 2012. [Xinhua]

Gulls fly over the Lhasa River in Lhasa, capital of southwest China's Tibet Autonomous Region, Nov. 25, 2012. [Xinhua]