我有以下模型:publicclassCourse{publicintId{get;set;}publicstringName{get;set;}}publicclassCourse_TutionCenter{publicintId{get;set;}publicintCourseId{get;set;}publicintTutionCenterId{get;set;}[ForeignKey("CourseId")]publicvirtualCourseCourse{get;set;}[ForeignKey("TutionCenterId")]publicvirtualTutionCen