Photo taken on May 26, 2018 shows a billboard of China International Big Data Industry Expo in Guiyang, capital of Southwest China's Guizhou province. The four-day expo opened here on Saturday, attracting over 40,000 participants from nearly 30 countries. [Photo by Ou Dongqu/Xinhua]

People visit the International Big Data Industry Expo in Guiyang. The four-day expo opened on May 26, attracting over 40,000 participants from nearly 30 countries. [Photo by Ou Dongqu/Xinhua]