Relative independence.For all-round development of subject of living,each form of activities such as symbolization,communication,operation,reflection and observation has unique functions and position that they cannot be replaced by one another.Every form of activities usually has the most direct value or function to development of subject's corresponding qualities.For example,symbolic learning is the most effective for cognitive development (especially development of linguistic and logic-mathematical intelligence) or development of subject as learner of book knowledge,while operative learning is most useful for developing skills to operate,and interactive learning is best for cultivating social competences (e.g.language ability,morality,co-operative spirit,interactive skills,empathy,conception of democracy and equality).If all-round development means to develop in students the qualities for engaging in multiple real life activities,the simultaneous employment of multiple types of learning is the basic condition for facilitating all-round development.