A staff (R) introduces an unmanned aircraft to a visitor during the 2018 Global Hard and Core Technology Expo held during the Global Hard and Core Technology Innovation and the Belt and Road Innovative Cooperation Conference 2018 in Xi'an, capital of northwest China's Shaanxi Province, on Nov. 8, 2018. The conference kicked off here on Thursday. A series of relative events will be held under the conference. (Xinhua/Shao Rui)