Whether the teaching content is appropriate, whether it meets the requirements of curriculum standards, teaching materials and research process; What is the depth and breadth of the teaching content? How many teaching contents are there, and how do students relate to each content? Whether the students feel and present the connection in this lesson, and present the connection between this lesson and what the students have learned and will learn; How do teachers explain the learning content to students, whether it is easy to understand and whether the language is concise and clear? Whether the students' learning results are consistent with what the teacher taught and what the students actually learned.