Of course, undergraduate students must be junior college students, and it is best to be the same as their own majors. You have been promoted to undergraduate course for 2 years, and it is not easy to change your major in 2 years! As for when, I don't know. The department should inform you. Choose a school carefully, which is the same as choosing a school in the college entrance examination! The number of students enrolled is fixed, so be careful not to be squeezed out. Therefore, if there is a college entrance examination in our school, it is best to take the joint exam. Relatively speaking, the chances of being admitted will be greater (the students in our school will take care of it).