There are two thousand students in this college are from the countryside.A. one-third of

问题补充：

There are two thousand students in this college, are from the countryside.

A. one-third of them

B. one-third of which

C. one-third of whom

D. one-third in which

答案：

A. one-third of them

B. one-third of which

(答案→)C. one-third of whom

D. one-third in which

解析：考查定从。先行词是students指人，所以关系代词要用whom；选C。