Participants adjust a robot during the Shandong provincial contest of the World Educational Robot Contest in Rizhao City, east China's Shandong Province, Oct. 26, 2019. The contest opened in Rizhao City on Saturday, attracting more than 2,600 young participants from home and abroad. The contest is an international event in educational robot industry and invites children and teens from 3 to 18 years old. (Xinhua/Wang Kai)