Liang Xijun (L), a senior engineer of the First Engineering Bureau of China Railway Group Limited, works with a colleague on a construction site in Xi'an, northwest China's Shaanxi Province, April 29, 2019. Over the past 13 years, Liang Xijun has developed from a new recruit to an expert in terms of subway construction by consistent learning and practicing. He participated in construction work of 5 subway lines and was awarded National Labor Medal and the May 4th Medal of Shaanxi Province. Under his leadership, the workshops named after him have owned several patent rights of invention, promoted new techniques, and prepared over 150 technical pillars for China. (Xinhua/Zhang Bowen)