A、Because they get low grades. B、Because they exhaust the reference sources in the library. C、Because they can spend only limite

Many teachers believe that the responsibility for learning lies with the student. If a long-reading assignment is given, instructors expect students to be familiar with the information in the reading even if they do not discuss it in class or on a given examination.(Courses are not designed merely for the students to pass exams.) The ideal student is considered to be one who is motivated to learn for the sake of learning, not the one interested only in get ting high grades. Grade-conscious students may be frustrated with teachers who do not believe it is necessary to grade every assignment. Sometimes home work is returned with brief written comments but without a grade.
    When research is assigned, the professor expects the students to take the initiative and to complete the assignment with minimal guidance. Professors expect students, particularly graduate students, to be able to exhaust the reference sources in the library.
    Professors will help students who need it, but prefer that their students do not be overly dependent on them. The time that a professor can spend with a student outside of class is limited. If a student had problems with classroom work, the student should either approach a professor during office hours or make an appointment.