1978年初冬,我有机会在北京市一所中学听了《中国石拱桥》的公开课。在整篇课文教学过程中,老师对课文第九段“建成的桥,用料省,结构巧,强度高”一语,避而不谈。在课后召开的讨论会上我曾提出:“在我国古代劳动人民建成的石拱桥中,有许多是惊人的杰作,其中最著名的是赵州桥和芦沟桥。可不可以在备课会上讨论一番,它们究竟在哪些地方表现出‘用料省,结构巧,强度高’这些特点 In the early winter of 1978, I had the opportunity to listen to the open course of “China Stone Arch Bridge” in a middle school in Beijing. Throughout the course of the lesson, the teacher evaded talks in the ninth paragraph of the text, “The bridge built, the materials used, the structure, and the intensity.” At the seminar held after class, I once said, “Many of the stone arch bridges built by the working people in ancient China are amazing masterpieces. The most famous ones are the Zhaozhou Bridge and the Lugou Bridge. Can we attend the preparation meeting? Discussions, where do they show ’material provinces, structures, high strength’?