Photo taken on June 24, 2021 shows a measuring robot at China Building Science Conference and Green Intelligent Building Expo in the national convention and exhibition center in Tianjin, north China. Tianjin holds the first Green Intelligent Building Expo from June 24 to 27, with a focus on new materials, latest technologies, new equipment, and new energy in the building industry. [Photo by Sun Fanyue/Xinhua]