【编辑观点】练习的厚度主要指横向的拓展和负载的充盈,即在以夯实基础知识为目的的练习基础上,要对教材内容适度进行横向拓展,以变式训练开阔学生视野,培养学生思维的广阔性和灵活性;要适度进行纵深挖掘,设计“少而精”的练习,让每一个练习负载更多的知识元素和思维元素, [Editorial] The practice of the thickness of the main refers to the lateral expansion and the filling of the load, that is, in order to lay a solid foundation for the purpose of practice based on the textbook should be appropriate horizontal expansion, training to broaden their horizons with variant training to develop students thinking The broadness and flexibility; to moderate excavation, design “less but fine” exercises, so that each practice load more knowledge elements and thinking elements,