Which of the following is NOT true according to the passage?
When a student is late for class, he / she must knock before he / she enters the classroom.
A student is thought to be impolite when he/she doesn't come for class on time.
A student is thought to be impolite when he / she takes off his / her shoes in the classroom.
A student is thought to be impolite when he / she eats and drinks in class.