异阶导函数能揭示函数在不同尺度上的变化特征，帮助深入理解函数行为。精A品A国A产A偷A拍A自A拍

　　In a class room, a girl is sitting on the desk, solving a math quiz. If she cannot solve it in time, a horrible thing is likely to happen. The clock is ticking but the quiz is not likely to be solved. And her mechanical pencil breaks down. However she has to solve the quiz.