On July 6, 2018, "Huayuworld.org" invited Prof. De-Fen Ou, Department of Teaching Chinese as a Second Language at Chung Yuan Christian University to give an online live lecture about "Teach and Learn Second Language in an Effective Way", which received favorable feedbacks from audiences. This video has uploaded onto youtube, please see
https://youtu.be/ddYEgVn-0Js