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 解析: 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。This is ________ pear. That’s ________ apple.A．a...aB．an...an　　　　 C．a...anD．an...a