The song in subject three is called "A Smiling River". The song "A Smile in the Rivers and Lakes" was originally a dramatic Chinese-style song with heroic lyrics. After clever adaptation, it broke through the traditional form of expression and transformed into a musical work that is loved by the public. The melody and rhythm were modified during the adaptation process. It has been given new vitality and turned into a modern pop music that crosses cultural boundaries and can be widely sung, showing a unique cultural fusion and artistic innovation. Although the inspiration for its name comes from "Subject Three", a popular dance on the Internet. It is a popular Internet meme and dance form that is used in "Subject Three" in the driving license test, but is not actually part of the test. It quickly became popular after netizens shared a video of a couple's wedding in October 2023. The subject three phenomenon reflects broader trends in how internet culture and memes are shaping modern entertainment and social interaction. It demonstrates how creativity in the internet age can transform seemingly ordinary elements into global sensations. The trend also highlights cultural dominance. The transformation of rights, where simple, interesting and universally appealing content transcends national borders and language barriers, attracting a wide audience in different countries.