Django - 在父级父级和父级中使用类作为内联

I have three class in my code. Exam, Question and QuestionResource. QuestionResource is a file and has a foreign key to Question.Also Question has a foreign key to Exam. Currently Question is included as inline in Exam's admin view. However it is seperately registered in the admin so I can both add question using its own admin or using the inline-view in Exam admin view.I have three class in my code. Exam, Question a