Attendees browse books during an education exhibition at the 12th National Chinese Language Conference (NCLC) in San Diego, the United States, on May 10, 2019. The 12th NCLC of the United States kicked off Thursday evening in the coastal city of San Diego in the western U.S. state of California. More than 1,300 teachers, administrators and policymakers from the United States and seven other countries took part in the three-day event. (Xinhua/Zhao Hanrong)