问题
There are altogether fifty-four students in our class, _____ is a new comer from a faraway mountain village.
A:the most diligent of who
B:but the most diligent of whom
C:the most diligent of them
D:of whom the most diligent
B:but the most diligent of whom
C:the most diligent of them
D:of whom the most diligent
正确答案是：
