数列历年来都是高考的重点,而且近几年高考对数列考查的分值似有增加趋势,同时数列综合题常出现两类的问题:交叉数列与子数列,不少同学解答起来有困难,本文结合实例谈谈这两类问题的形式与求解. The number of columns over the years are the focus of college entrance examination, and college entrance examination in recent years on the scores of the series seem to increase the score, while the number of comprehensive questions often appear two types of problems: cross number and sub-number of columns, many students have difficulty in answering them, This article talks about the forms and solutions of these two types of problems with examples.