Many teachers believe that the responsibilities for learning lie with the students. 【小题1】a long reading assignment is given，instructors expect students to be familiar with 【小题2】(inform) in the reading even if they do not discuss it in class. The ideal student is considered to be one who is motivated to learn for the sake of learning，not the one interested only in getting high grades. Sometimes homework is returned 【小题3】brief written comments but without a grade. Even if a grade is not given，the student is responsible 【小题4】learning the material assigned. When research 【小题5】(assign), the professor expects the student to take it actively and to complete it with minimum guidance. It is the student's responsibility to find books，magazines，and articles in the library. Professors do not have the time to explain 【小题6】a university library works；they expect students，【小题7】(especial) graduate students, to be able to exhaust the reference origins in the library. Professors will help students who need help, but prefer that their students should not be too dependent on them. In the United States，professors have many other duties 【小题8】teaching, such as doing research. Therefore, the time 【小题9】a professor can spend with a student outside of class 【小题10】(limit). If a student has problems with classroom work，he should either approach a professor during office hours or make an appointment.