When asking the teacher the topic of the thesis, express your interest in the research, and ask the teacher in an open way if you have any recommended topics or suggestions. This way shows respect for teachers' professional opinions, and also makes teachers feel your serious attitude towards research. In the actual conversation, you can further explain your research direction and interest points, so that teachers can provide relevant suggestions more accurately. This way of communication helps to establish a good relationship between teachers and students and improve the quality of topic selection.