一道非谓语动词的选择题

— Li Hua is said ______ abroad for four years. Do you know which country he studied in?

—Australia.

A. to have studied

B. studying

C. to be studying

D. having studied

请问选择什么？为何？

选 A. to have studied，不定式的完成式（也叫：完成体），说明动作发生在is said 之前，此前已经在海外深造4年了。又如：

He is said to have moved to Chicago.

据了解他已搬到芝加哥去了。

She is said to have been an actress about twenty years ago.

据了解她在20年以前曾是一位女演员。

Columbus is said to have discovered America in 1492.

据了解哥伦布于1492年发现了美洲。