上课铃比忐忑还忐忑下课铃比国歌还悦耳
[shàng kè líng bĭ tăn tè hái tăn tè xià kè líng bĭ guó gē hái yuè ĕr]
This humorously compares the sound of a school bell—feeling more uneasy at the beginning of class ('more unsettling than anxiety itself') and finding relief or enjoyment (like hearing a national anthem) at the end of classes, thus reflecting school life and its stresses and comforts.