–Who is the man talking to the headmaster?–A professor a visit to our school.A. paysB. is

问题补充：

–Who is the man talking to the headmaster?

–A professor a visit to our school.

A. pays

B. is paying

C. paid

D. paying

答案：

A. pays

B. is paying

C. paid

(答案→)D. paying

解析：考查非谓语动词。句意:和校长说话的那个人是谁呀？是一位正在参观我们学校的一名教授。教授与访问之间是主动关系，所以用现在分词paying，在这里作后置定语。故选D。