练习是学生巩固新知获得能力的必要手段。教学实践也表明,并不是练习做得越多就越好。在平时的教学中,很多有经验的老师会将几道有内在联系的题目,按照一定的逻辑顺序,汇编成有针对性、层次性、发展性的题组让学生集中练习。这样精心组合的题组,能充分发挥其整体功能,优于无组织的分散练习。这样的题组能纠正错误、查漏补缺,还能帮助学生提升思维品质、形成知识结构。一、设计“对比型”题组,在辨析中凸显本质特征 Exercises are necessary tools for students to acquire their new knowledge. Teaching practice also shows that not the more you practice, the better. In normal teaching, many experienced teachers will be a few internal links with the subject, according to a certain logical order, compiled into targeted, level, development of the group to allow students to focus on practice. This group of carefully combined questions, give full play to its overall function, better than the non-organized scattered exercises. This problem group can correct mistakes, leaks, but also to help students improve their thinking quality, the formation of knowledge structure. First, the design “contrast type ” title group, highlights the essential characteristics in the analysis