— Have you ever visited the Opera House?—YesWhen I was in Sydney I it twice．A. have vis

问题补充：

— Have you ever visited the Opera House?

—Yes．When I was in Sydney, I it twice．

A. have visited

B. had visited

C. visited

D. would visit

答案：

A. have visited

B. had visited

(答案→)C. visited

D. would visit

解析：

这题考查时态题：因为时间是When I was in Sydney，所以用过去时，句意是：--你参观过歌剧院吗？--是，当我在悉尼的时候，我去过两次。选C。