there＇s an old chinese saying: "the teacher is not qualified, if he is not strict with his students." so we can see that in former times the relations between students and teachers were serious and formal. but nowadays, maybe because of the western influence, this kind of re lations becomes less formal and more friendly, especially at colleges and universities.
college students don＇t have to stand up when the teacher comes into the classroom. students are generally encouraged to ask questions during class, to go to the professor＇s office for help or to have a discussion with the tutor after class, and to phone if they need help in their lessons.
however, students are still epected to be polite to their teachers. when students want to ask questions, they usually raise their hands first and wait until they＇re allowed to speak. but if a professor is giving a formal lecture, it is the wrong time to ask a question. if you de so, you are rude enough to offend the lecturer and the other classmates.