Photo taken on May 23, 2018 shows a subway cabin decorated with elements of Qingdao in Qingdao, east China's Shandong Province. The coastal city will host the 18th summit of the Shanghai Cooperation Organization (SCO) in June. (Xinhua/Zhang Cheng)

A couple pose for wedding photos on a beach in Qingdao, east China's Shandong Province, May 4, 2018. The coastal city will host the 18th summit of the Shanghai Cooperation Organization (SCO) in June. (Xinhua/Zhang Cheng)

People have meal at a restaurant in Qingdao, east China's Shandong Province, May 18, 2018. The coastal city will host the 18th summit of the Shanghai Cooperation Organization (SCO) in June. (Xinhua/Guo Xulei)