Most of the professors to our school were from South Africa．
A. invited
B. to be invited
C. being invited
D. had been invited
网友回答
(答案→)A. invited
B. to be invited
C. being invited
D. had been invited
解析：考查非谓语动词的用法。Professors 与invite之间是逻辑上的被动关系,所以用过去分词作定语,表示完成和被动的意义。