They suggested that the professor just now should be made chairman of the meeting.
A. referring to
B. referring
C. referred to
D. referred
网友回答
A. referring to
B. referring
(答案→)C. referred to
D. referred
解析：考查非谓语动词作定语。the professor 与refer to 为动宾关系所以用过去分词作定语。句意：他们建议刚才提到的那位教授应该当会议主席。