1. What did you do? 2. What is the current hotspot in this research field? 3. What's the innovation in your research work? 4. What problems do you think need to be further solved in this field? Summarize the main conclusions of your research in a few sentences. The above contents are common sense questions that will appear in most defenses, including: Are the formats of figures and tables in the paper correct? Are the number and format of references standardized? Is it a document from recent years? As well as the experimental data (figures and tables) appearing in the defense ppt, you may have to explain, and the rest depends on the scene. Good luck.