—You were brave enough to raise objections at the meeting.
— Well, now I regret ________ that.
D
regret后所跟动词有todo与doing两种形式，不定式表示“为做某事而遗憾”，doing表示“为做过某事而后悔”。“havingdone”则更强调动作已发生而无法挽回。
Thetrafficwasheldupformorethanthirtyminutes,________causedmetoarrivelate.
You’d better leave things ________ if you don ’t know how to deal with them