The examination results in the speech of our headmaster delighted all of us.
A. refer to
B. referring to
C. was referred to
D. referred to
网友回答
A. refer to
B. referring to
C. was referred to
(答案→)D. referred to
解析：考察过去分词作定语。The examination results与refer to构成被动关系。所有使用过去分词短语Referred to in the speech of our headmaster修饰名词短语the examination results.