假如你是李华，你的英国笔友Lisa来信说她最近正在学习汉语，在学习过程中遇到"程门立雪"（ Cheng Men Li Xue）这一成语，不解其意，请你根据下面图片提示，用英语给她回信，简要叙述这个成语故事，并谈谈自己的理解和感悟．

要求：

1．语言规范，语句通顺，可适当发挥；

2．字数：100词左右，开头和结尾已经给出，不计人总词数．

可能用到的词： idiom成语； during the Northern Song Dynasty北宋时期；Cheng Yi程顾； have a nap小憩； disturb打扰； moved感动的； respect尊敬

Dear Lisa，

     I'm glad to hear from you．___________________________

                                                                                                                                                                                                                                                                            Yours，

                                                                                                                                                                                                                                                                             Li Hua