【单选题】

Many teachers believe that the responsibilities for learning lie with the student. (21) a long reading assignment is given, instructors expect students to be familiar with the (22) in the reading even if they do not discuss it in class or take an examination. The (23) student is considered to be (24) who is motivated to learn for the sake of (25) , not the one interested only in getting high grades. Sometimes homework is returned(26) brief written comments but without a grade.Even if a grade is not given, the student is (27) for learning the material assigneD、

When research is (28) , the professor expects the student to take it actively and to complete it with (29) guidance. It is the (30) responsibility to find books, magazines, and articles in the library. Professors do not have the time to explain (31) a university library works; they expect students, (32) graduate students, to be able to exhaust the reference (33) in the library. Professors will help students who need guidance, but (34) that their students should not be (35) pendent to them. in the United States professors have many other duties(36) aching, such as research work.
(37) the time that a professor can spend with a student outside of class is (38) If a student has problems with classroom work, the student should either (39) a professor’s office (40) e an appointment with the professor.
A．If
B．Although
C．Because
D．Since