This was returned because the person____this letter was addressed had died three years ago.
问题描述：
This was returned because the person____this letter was addressed had died three years ago.
A.to whom B.to which C.which D.whom
答
这是一个定语从句,this letter was addressd做the person 的定语,如果把定语和主语拿出来,应该是this letter was addressd to the person.因此有介词to