Li Di, chief scientist at the National Astronomical Observatories of China (NAOC), introduces the findings of two pulsars by the China-based FAST, the world's largest single-dish radio telescope, in Beijing, capital of China, Oct. 10, 2017. After one year of trial operation, the FAST has identified two pulsars, the NAOC said Tuesday. Located in a naturally deep and round karst depression in southwest China's Guizhou Province, FAST, which stands for Five-hundred-meter Aperture Spherical Radio Telescope, was completed in September 2016. (Xinhua/Jin Liwang)