-Taking into account regional differences and differences in teaching level. Different provinces and cities have different levels of economic development, educational resources, cultural characteristics and students' needs. If the teaching materials are unified, they may not be able to adapt to the actual situation in various places? .

-Promoting the innovation and reform of teaching materials. If there is only one set of teaching materials, it may form monopoly and rigidity, which is not conducive to the updating and improvement of teaching materials. Multiple sets of teaching materials can compete with each other and learn from each other to improve the quality and diversity of teaching materials? .

-Ensure the correctness and completeness of teaching materials. If there is only one set of teaching materials, once there are mistakes or defects, it will affect primary and secondary school students all over the country. Multiple sets of teaching materials can be proofread and supplemented with each other to avoid singleness and one-sidedness? .