WhenIentered,theyweretalkingabouttheteachersandschools　...

问题详情：

When I entered, they were talking about the teachers and schools　　　　they had visited.

A. which            B. whom         C. that             D. who

【回答】

 C。当先行词既包含人又包含物时, 关系代词只能用that, 因为that可指人, 也可指物。

知识点：定语从句

题型：选择题