This is easy to say. At that time, I also did social practice during the winter vacation. I don't need to introduce it in detail. You can take some photos of your school online or by yourself (after all, it is your own school) to do some ppt. Before freshman year, students should have made a promotional film, and so can clubs.

Senior three students know more or less about the official introduction of universities. What you need is not to repeat those, but to tell your experiences in college, which are interesting, interesting and bad. Humor will have a better effect.

Teachers shouldn't give you too much time. After all, it is the third year of high school.