自助餐式的作业。镜头之一:“同学们,今天我们学习了‘时间的简单计算’,请大家回顾一下,你还有什么知识掌握得不是太好?”“老师,求第一天某个时刻到第二天某个时刻所经过的时间是多少,我有些困难。”……“那你们就根据自己的学习情况,先复习一下相关例题,再模仿例题编一两道类似的题目考考自己。好吗?”镜头之二: Buffet-style homework. One of the shots: “My classmates, today we have studied 'Simple Calculation of Time'. Please review what is your knowledge?” “Teacher, asking for a moment from the first day to the next day At some point the time elapsed is much, I am a little bit difficult. ”...“ Then you according to their own learning situation, review the relevant examples, and then imitate the example of a series of two or two similar topics test yourself. ”Lens two: