Question

[W51] She brought with her three friends, none of _____ I had ever met before.

A. them B. who C. whom D. these
翻译，并分析。
答案C

Answer 1

她带了三个朋友，没有一个是我之前见过的。
这是定语从句，首先排除A和D，I had ever met before修饰的是 her three friends，所以先行词是 her three friends，而且在从句中 her three friends是宾语，所以要用whom。

Answer 2

C. whom--------此处是非限制性定从
她带来3个朋友，没有一个是我以前曾经见过的。