People look at a model of China's Five-hundred-meter Aperture Spherical Radio Telescope (FAST), the world's largest single-dish radio telescope, during the International Big Data Industry Expo in Guiyang, capital of southwest China's Guizhou Province, May 26, 2018. The four-day expo opened here on Saturday, attracting over 40,000 participants from nearly 30 countries. (Xinhua/Liu Xu)