The retired teacher is said to have returned from the USA where he by some of his old st

问题补充：

The retired teacher is said to have returned from the USA, where he by some of his old students.

A. would be visited

B. visited

C. had been visited

D. have been visited

答案：

A. would be visited

B. visited

(答案→)C. had been visited

D. have been visited

解析：句意：据说这个退休的教师已经从美国回来了，在美国他的一些学生拜访了他。主语时态为一般现在是，非限制性定语从句中他被学生拜访，语态为被动，故排除A和B。“被拜访”这个动作发生在过去，故选用过去时态，排除D。故选C。