题目

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： A 根据句中的 studied 可知，他曾到国外留过学，也就是说“留学”这个动作已结束并发生在谓语动作(is said)之前，故用完成式，即选 A。  

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