1, roll call one by one and enter the classroom point by point. There are no advantages, no alternative answers (this is the key), and long disadvantages.

Hand in a student ID card when you enter the classroom and take it away when you leave the classroom. The Academic Affairs Office has specially set up a computer statistical system, which can solve the attendance problem of the whole school (the Academic Affairs Office has already checked the number of students, so it is not difficult for him to do this work). None of the advantages will be missed, and there will be no substitute classes. Disadvantages These students will be miserable. They can't even do what they want in cut class.