Study on Chinese acquisition and teaching of deaf students from the cognitive perspective 并列题名:Study on Chinese acquisition and teaching of deaf students from the cognitive perspective Study on the transformation and upgrading of commerce and trade industry from the international perspective Study on the Chinese and Japanese dream record from a comparative perspective Study on the knowledge gap hypothesis in the context of new media from the qualitative perspective 并列题名:Study on the transformation and upgrading of commerce and trade industry from the international perspective