students never call teacher’s name directly, listening class without a move, taking a note, and raising up hands means he or she is preparing for answering questions. In the United States, students sit face to face, and take a relax pose in the class, drinking beverages and talking freely are permitted. I think, this phenomenon represents different culture background. Chinese respected teachers since Confucius time, so any thing irrelevant are considered as a disrespect manner, while American culture believes that every person is equal, and students have the rights of drinking and expressing their points.
有难度!