Peng Guolong teaches his apprentices selecting material of mask of Nuo Opera in Xiangdong District of Pingxiang, east China's Jiangxi Province, Dec. 28, 2017. Mask is an important element of Nuo Opera, which was listed as one of the national intangible cultural heritages. Chen Quanfu and Peng Guolong are the inheritors of Xiangdong Mask of Nuo Opera. The craft calls for a great deal of times as well as mastery. Chen can carve 400 types of masks and Peng creates many new models on the basis of traditional skill. (Xinhua/Peng Zhaozhi)