Hello, Zhibo. First of all, you should contact the teacher. When you send an email to the teacher, you should introduce yourself, mainly what you have learned in the undergraduate course and what your study, life and work are like. Then you can tell me why you chose this teacher. In addition, you can write down your own awards and wait for the teacher's reply. In fact, it is best to meet the teacher. I think the focus of the subject depends on which direction you apply for. I am solid mechanics, so the emphasis is on materials. I think it's too early for you to broadcast live. I suggest you do your undergraduate study hard first. Tsinghua attaches great importance to undergraduate achievement and all-round development. Wait until your junior year next semester to talk about direct blogging.