Cheng Gang polishes Guqin, a seven-string traditional Chinese instrument, at his studio in a Guqin museum in Xi'an, northwest China's Shaanxi Province, Oct. 18, 2018. Cheng Gang is a representative inheritor of Tang Dynasty (618-907 AD) styled Guqin making technique, an intangible cultural heritage of Shaanxi Province. With dozens of procedures required, making each set of Guqin takes him over two years. Over the ten years of his career as a Guqin maker, Cheng has made more than 100 sets of Guqin and educated several apprentices. He set up an academy in 2013 on the research, archaeology and education of Guqin, and established a Guqin museum in 2017 to popularize Guqin culture. (Xinhua/Shao Rui)