现在分词的完成式主要用在状语中，表示这个动作在谓语所表示的动作之前完成。
【例如】
Having succeeded in the last examination, she was more confident of another success in the coming one.
Having found the cause, they were able to propose a remedy.
Having finished his homework, the boy went to play computer game.Notshavingsmade adequate preparations, they thought it better to postpone the excursion till next week.
独立结构中也可以用现在分词的完成形式。
【例如】
His parentsshavingsdied, the orphan is now taken care of by the government.
The guestsshavingsleft, they resumed their discussion.
