old_contents: from django.contrib import admin
  from models import Teacher, Student, Book, Lesson, Word
  
  admin.site.register(Teacher)
  admin.site.register(Student)
  admin.site.register(Book)
  admin.site.register(Lesson)
  admin.site.register(Word)
  
new_contents: from django.contrib import admin
  from django.contrib.auth.admin import UserAdmin
  from django.contrib.auth.models import User
  
  
  from models import Teacher, Student, Book, Lesson, Word
  
  
  class TeacherInline(admin.StackedInline):
      model = Teacher
      can_delete = False
      verbose_name_plural = 'teacher'
  
  
  class UserAdmin(UserAdmin):
      inlines = (TeacherInline, )
  
  admin.site.unregister(User)
  admin.site.register(User, UserAdmin)
  
  admin.site.register(Teacher)
  admin.site.register(Student)
  admin.site.register(Book)
  admin.site.register(Lesson)
  admin.site.register(Word)
  
subject: Implement TeacherInline to make it a admin