Photo shows Tibetan people from the Yushu Tibetan Autonomous Prefecture in northwest China’s Qinghai Province are getting sands and stones into shapes of the mantra and symbols engraved on Mani stones on the frozen Tongtian River, Feb.2, 2018. [Photo/China News Service]

Photo shows Tibetan people from the Yushu Tibetan Autonomous Prefecture in northwest China’s Qinghai Province are getting sands and stones into shapes of the mantra and symbols engraved on Mani stones on the frozen Tongtian River, Feb.2, 2018. [Photo/China News Service]

Photo shows Tibetan people from the Yushu Tibetan Autonomous Prefecture in northwest China’s Qinghai Province are getting sands and stones into shapes of the mantra and symbols engraved on Mani stones on tdhe frozen Tongtian River, Feb.2, 2018. [Photo/China News Service]

Photo shows Tibetan people from the Yushu Tibetan Autonomous Prefecture in northwest China’s Qinghai Province are getting sands and stones into shapes of the mantra and symbols engraved on Mani stones on the frozen Tongtian River, Feb.2, 2018. [Photo/China News Service]

Photo shows Tibetan people from the Yushu Tibetan Autonomous Prefecture in northwest China’s Qinghai Province are getting sands and stones into shapes of the mantra and symbols engraved on Mani stones on the frozen Tongtian River, Feb.2, 2018. [Photo/China News Service]