12.1 He had a son and a daughter ,__ taught at the same school.
问题描述：
12.1 He had a son and a daughter ,__ taught at the same school.
He had a son and a daughter ,__ taught at the same school
A.that B.both of whom
C.neither of them D.both of them
答
B
这里考查的是定语从句.the same school提示应该是都在那所学校教书,排除C（都不在）；
然后这里whom指代a son and a daughter .如果用them,应该是有连词之类的或两个句子中.