Then there is the teacher's problem. There will be something about the content of the paper. This kind of question is simple. Other teachers will ask some divergent questions related to your paper. Of course, I have also seen teachers arguing over a question and leaving the respondents aside. Ha ha. Anyway, you should prepare a sentence first and recite it. Familiarize yourself with your papers. Of course, it is better to know the relevant content. Domestic universities are in this order. Good luck with your defense.