单选题During the tourist season

问题补充：

单选题Duringthetouristseason,therearemanypeoplewanderinginthiscitytoseetheoldcastles_____inthesixteenthcentury.A.to be builtB.being builtC.having been builtD.built

答案：

D解析非谓语动词的动作先于句中谓语动词的动作时， 用过去分词。