题目内容：
根据材料，完成题。Unpopular Subjects?
Is there a place in today's society for the study of useless subjects in our universities? Just over 100 years ago Fitzgerald argued in a well-written letter, (51) Nature that
Universities must be allowed to study useless subjects (52)they don't, who will? He went on to use the (53) of Maxwell's electrodynamics ( 电动力学 ) as one case where a useless subject" has been transformed to a useful subject.
Nowadays this argument is again very much (54) in many universities. Indeed one suspects that it is one of. those arguments that must be (55) anew (重新) by each generation. But now there is an added twist__________ subjects must not only be useful, they must also be (56) enough that students will flock (蜂拥) to do them, and even flock to pay to do them.
As umversities become commercial operations, the pressure to (57) subjects or departments that are less popular will become stronger and stronger, Perhaps this is most strongly (58) at the moment by physics. There has been much (59) in the press of universities that are closing down physics departments and incorporate them with mathematics or engineering departments.
Many scientists think otherwise. They see physics as a (60) science, which must be kept alive if only to (61) a base for other sciences and engineering. It is of their great personal concern that physics teaching and research is under (62) in many universities.
How can it be preserved in the rush towards commercial competition? A major turnaround (转变) in student popularity may have to (63) until the industrial world discovers that it needs physicists and starts paying them well.
Physics is now not only unpopular; it is also “hard". We can do more about the latter by (64)teaching in our Schools and universities. We can also (65) cooperative arrangements to ensure that physicists keep their research and teaching up to date.
请在第__(51)__处填上正确答案。 A．about
B．of
C．to
D．on
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