今天换笔芯，忽摸有陷凹感，细观，见指磨得一深壕。然即吟。

                                                                            绝句

                                                     莫道教书轻简好，

                                                                 更三夜半总常熬。

                                                                 批得作业知多少，

                                                                 笔杆磨失陷一凹。