Tourist visit Taishan Mountain in Tai'an City, east China's Shandong Province, May 21, 2019. (Xinhua/Guo Xulei)

Aerial photo taken on May 20, 2019 shows the scenery of Taishan Mountain in Tai'an City, east China's Shandong Province. (Xinhua/Guo Xulei)

Aerial photo taken on May 20, 2019 shows the scenery of Taishan Mountain in Tai'an City, east China's Shandong Province. (Xinhua/Guo Xulei)

Aerial photo taken on May 20, 2019 shows the scenery of Taishan Mountain in Tai'an City, east China's Shandong Province. (Xinhua/Guo Xulei)

Tourist visit Taishan Mountain in Tai'an City, east China's Shandong Province, May 20, 2019. (Xinhua/Guo Xulei)

Photo taken on May 20, 2019 shows the scenery of Taishan Mountain in Tai'an City, east China's Shandong Province. (Xinhua/Guo Xulei)

Photo taken on May 20, 2019 shows the scenery of Taishan Mountain in Tai'an City, east China's Shandong Province. (Xinhua/Guo Xulei)