Photo taken on Jan. 19, 2018 shows a watermill which is used to extract tea oil in Shanwei Village of Banlan Town in Rong'an County of Liuzhou, south China's Guangxi Zhuang Autonomous Region. The village adopted traditional method to extract tea oil and the price of tea oil here increased from 80 yuan (about 12.5 U.S. dollars) per kilograms to 120 yuan (about 18.8 U.S dollars) per kilograms yet the demand still exceeds the supply. (Xinhua/Tan Kaixing)