1, which is not called at ordinary times, but will be called in disguise by handing in homework.

2. Several classes in the new semester will be named, in order to let the teacher remember the students' names and let everyone know themselves.

3. Later the roll call was not made public. The teacher will record the people who come to class on the computer and start the class. The order of roll call is arranged according to the initials of the surname of the class. If the surname is A, the roll call will arrive first. If the surname starts with z, it will be called at last.