–Who is the man talking to the headmaster?
–A professor a visit to our school.
A. pays
B. is paying
C. paid
D. paying
网友回答
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。