Children read books at a bookstore in Yan'an, northwest China's Shaanxi Province, July 30, 2019. As a part of the 29th China National Book Expo, which was held in Xi'an, northwest China's Shaanxi Province from July 27 to 30, four venues in Yan'an exhibited nearly 100,000 books of various kinds. (Xinhua/Liang Aiping)