It seems that you can't choose professional limited courses ... there are loopholes in our student system. One of my classmates just took the last class, and then finally the academic affairs office wouldn't let the teacher grade. Later, the investigation found that there was a BUG in the student system that allowed students to choose courses, so they changed it and did not let them rebuild. I ran to several departments to find a teacher. It's hard to say. If you don't intend to apply for early graduation, don't bother.