[读者来信] 夏新桥老师: 您好!我是一个数学爱好者,我想您也是吧.您的大名是我在《中学生数学》上找到的.在许多期的趣味数学、数苑纵横等栏目中,我都找到过您发表的一些文章.读了之后,我感到耳目一新,特别是《穿墙术》、《算两次》等等.我想您在数学方面的研究一定很有造诣. 在我的学习过程中碰到了两道难题,历时近两年至今未解决,下面恳请夏老师,为我解 [Reading letter from the reader] Xia Xinqiao: Hello! I am a math enthusiast. I think you are right. Your name is what I found in “Middle School Mathematics”. In many periods of fun maths, several aspects, etc. In the column, I have found some articles published by you. After reading this, I feel refreshed, especially with “Wall Wall”, “Calculate Twice”, etc. I think your research in mathematics must be very successful. In the course of my study, I encountered two problems that have not been resolved in the past two years. Please ask Xia Xi to explain it to me.