问题
选择题
Robert is said _______ abroad, but I don’t know what country he studied in.
A．to have studied
B．to study
C．to be studying
D．to have been studying
答案
答案：A
由 studied 可知，他曾到国外留过学，“留学”这个动作已结束并发生在谓语动作(is said)之前，所以要用完成式。