Children and adults read books during a book fair in Nanning, capital of south China's Guangxi Zhuang Autonomous Region, April 21, 2018. April 23 marks the World Book Day, which was promoted by UNESCO as a worldwide celebration of reading since 1995. (Xinhua/Yu Xiangquan)

Children and adults read books at Lunan Bookstore in Zaozhuang City, east China's Shandong Province, April 22, 2018. April 23 marks the World Book Day, which was promoted by UNESCO as a worldwide celebration of reading since 1995. (Xinhua/Sun Zhongzhe)