练习是学习者对学习任务的重复接触或重复反应．为使练习对学生的学习真正起到巩固、发展、深化和激励作用，通过练习使学生有所获、有所悟，并体验到成功和欢欣，练习的设计就必须遵循学生的认知规律，由浅入深，循序渐进，使练习具有层次性．练习一般分为基本练习、发展性练 Exercises are repeated or repeated responses of learners to learning tasks. In order to make the practice truly consolidate, develop, deepen, and stimulate students’ learning, through practice, students gain and realize, and experience success and happiness. The practice design must follow the students’ cognitive laws. From shallow to deep, step by step, so that the exercise is hierarchical. Exercises are generally divided into basic exercises and developmental exercises.