How to fill in the subject of the email when contacting the graduate tutor?

When is the best time to bring holiday greetings, such as "Celebrating the 70th anniversary of the victory of China people's War of Resistance against Japanese Aggression and the world anti-fascism", or "Happy New Year's Day", we will get to the point next time. \x0d\ Dear Professor X: \ x0d \ x0d \ Hello! Who am I in the X major? I studied under Professor X, and because I admire your leading major in biochemical engineering, I entered the postgraduate program of Huali Biochemical Engineering this year, so I was lucky enough to get a second interview. \x0d\\x0d\ I also searched some teachers' articles when I wrote my thesis before, and I was also very interested in X's teachers, so I chose the topic about X when I chose the topic for my graduation thesis. After reading some information from the teacher, I have great respect for your achievements in the X circle, and I very much hope to be a teacher, your graduate student and get guidance from the teacher. \ x0d \ x0d \ for myself, I also made careful thinking and evaluation. I think the knowledge and experimental skills I have learned during my four years in college are qualified to assist you in your research. During the undergraduate course, basically all professional courses and experiments reached more than 90%, with a solid theoretical foundation and strong hands-on ability, among which X course even got the highest grade score. Secondly, my English ability is ok, and I have passed CET-6. \x0d\ In addition, I have a strong interest in scientific research. I participated in the X project and won the X prize. At present, I am doing the graduation project of X in X laboratory of our school. Finally, I am cheerful, have a correct attitude, do things conscientiously, and know how to save and cherish life. I think my goal is clear and I can keep moving towards it. I have always believed in "Heaven rewards diligence", and I believe that through diligent study and work, I will gain something. \ x0d \ x0d \ I sincerely hope to be your student and accept your guidance. Of course, I will try my best to prepare for the second exam and try to get a high score to make up for the failure of the initial exam, so that I can become a teacher and your student. \x0d\ I think my greatest strength is my correct attitude, and I believe I can complete the task assigned by my teacher. If I don't pass the exam, I will always pay attention to you and hope to get your guidance in the future. \x0d\\x0d\ Thank you very much for taking the time to read my recommendation letter. I look forward to joining your research team. I wish you good health and smooth work. From \ x0d \ x0d \ xx.