Etiquette teacher Lu Min (1st R) instructs volunteers for the 18th Shanghai Cooperation Organization (SCO) Summit in Qingdao, east China's Shandong Province, June 5, 2018. More than 20,000 volunteers have been mobilized to offer services for the summit, from assisting with guests' arrival and departure, translation, and media requests, to the operation of city functions such as transportation, telecommunication, and banks. (Xinhua/Li Ziheng)