Because they usually receive the same score in the exams, there’s often disagreement as to

Because they usually receive the same score in the exams, there’s often disagreement as to is the better student, John or Mary.
A. whom
B. which
C. that
D. what

A. whom(答案→)B. whichC. thatD. what解析：本题考查宾语从句引导词的使用。本题引导词指人，因为是有范围的选择(John or Mary)，因此用which不用who。句意：因为他们总是得到同样的分数，关于谁是更好的学生，总是有分歧。选B。

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