People find their books on computers on April 21 to mark World Book Day. People in Zhangye city, in northwest China's Gansu province, celebrated World Book Day on April 23 by taking part in a variety of reading activities. With the development of the Internet, various reading modes have become available, such as online, mobile and tablet reading. China has attached great importance to reading this year since the 2015 national government work report pointed out the importance of reading nationwide. Reading is assumed to facilitate innovation and personal and social development. [Photo/xinhuanet.com]