Students at school must pass the required courses of their major. If you fail, you need to retake the exam and you can't change the subject. You can get credit for retaking the exam, but it will affect your grade point. If you fail the elective course, you can change to other courses, and finally you just need to complete the credits as required.
Students who have obtained the total credits and various credits specified in the talent training program within the specified study period are allowed to graduate and issue graduation certificates. The diploma needs enough credits, and the total credit for four years is about 170- 180, depending on the major.
The bachelor's degree certificate not only needs to have enough grade points, but also needs to pass CET-4 (if CET-4 fails, CET-4+CET-4 score > 646 is required).