问题
选择题
Helen was much kinder to her youngest son than to the others, __________, of course, made the others envy him.
A．who
B．that
C．what
D．which
答案
答案：D
这是一句非限制性定语从句，关系代词指代整个句子Helen was much kinder to her youngest son than to the others，且从句中行为动词made是主动语态，因此选择which。