在教学中,对学生容易混淆的概念,容易出现的不合理的推理论证,事先指出,打预防针,帮助学生“防患于未然”,是很必要的。但有时又要让学生从错误中接受教训,使学生“吃一堑长一智”,这样的教学效果往往比预防的办法还好。 In teaching, the concept of easy confusion for students, prone to unreasonable reasoning argument, pointed out in advance, playing preventive measures to help students “take preventive measures” is necessary. But sometimes students are taught to learn from their mistakes so that they can “eat and learn”. Such teaching tends to be better than preventive measures.