In the cafeteria, I saw my sister and her three friends, none of I had ever seen before.
A. them
B. which
C. whom
D. those
网友回答
A. them
B. which
(答案→)C. whom
D. those
解析:考察定语从句。本题定语从句的先行词是my sister and her three friends,关系代词whom指代先行词my sister and her three friends作为介词of的宾语。因为先行词是人,且作为宾语,故使用whom。AD两项不能引导定语从句,which的先行词是物。故C正确。