20 0 1年 1 0月中旬 ,笔者参加了本市高二教研活动 ,听了两堂旧版《代数》下册“数列”中的数列概念课的教学 .在这两堂课中 ,老师都把“数列和集合的关系”作为一个重要内容来讲解 .课堂效果表明 :两位老师都没有把这个问题讲清楚 ,相反地因为提了这个问题却又没有把它说明白 In mid-October, 2010, the author participated in the high school teaching and research activities in the city and listened to the teaching of the series of concept lessons in the two volumes of the “Algebra” in the second volume “Numbers.” In these two classes, the teachers all put “ The relationship between series and collections is explained as an important content. The classroom effect shows that neither teacher explained this issue clearly. On the contrary, because he raised this issue, he did not explain it.