Several professors from Peking University came to visit our school to my surprise one of

问题补充：

Several professors from Peking University came to visit our school, to my surprise, one of was my aunt.

A. them

B. those

C. which

D. whom

答案：

A. them

B. those

C. which

(答案→)D. whom

解析：考查非限制性定语从句，先行词是Several professors，定语从句中one of后面用关系代词whom引导定语从句，句意：几个来自北京大学的教授来参观我们学校，使我惊讶的是，一个是我阿姨。选D。