说明：  自适应课堂作业，用直接自校正和间接自校正实现控制问题，直接自校正中考虑了零极点相消和零极点不相消的问题
(Self-adaptive classroom work, using direct self-correction and indirect self-correction to achieve control problems, the problems of zero-pole cancellation and zero-pole cancellation are considered in direct self-calibration)