上课睡觉下课乱跳考试死翘
[shàng kè shuì jué xià kè luàn tiào kăo shì sĭ qiáo]
Describes a rather lazy but vivid student's lifestyle - sleeping in class, behaving erratically after school, and slacking off during exams. In brief, showing lackadaisical attitude towards academics mixed with high-energy behaviors outside of studying hours.