Introduction to the Golden Bell of Muduo: "The Analects of Confucius·Bayi No. 3" says: "The world has been without virtue for a long time, and the heaven will regard the Master as Muduo." According to literature, "Duo" probably originated in the Xia and Shang Dynasties. It is a metal-framed sounding instrument. The one with wood as its tongue is called Mu Duo, and the one with gold as its tongue is called Jin Duo; Mu Duo is Wen, used to announce government affairs; Jin Duo is Wu, used to command the army. Confucius used Muduo to describe himself, saying that he was sent by God to educate the people. Because Confucius has been engaged in education for many years, "Muduo" has since become an alias for teachers, and the wooden tongue of Muduo can be compared to the teacher's "educational tongue." Therefore, Beijing Normal University uses "Muduo" as its school emblem, and a university uses "Muduo", a symbol of the world, as its own logo, which shows its ambition.