1. When the teacher comes in the classroom, the students needn’t stand up.
2.Students are allowed to enter class late or leave early(by most teachers), if necessary.
3.然而，学生们仍然要对老师和同学有礼貌并在考试期间保持安静。
4.In the eyes of most American teachers, students who are talking to each other during a test are cheating5.The relationship between students and teachers is less formal in the U.S. than in many other countries,
especially at the college level.