总结：现在分词的完成式： having done. 表示动作发生在谓语动词之前。

否定式： _______________________

被动式： _______________________

练习：1). ______________________(live) with the girl for 5 years, we all know her very well.

2). ______________________ (meet ) her, I couldn't tell you what she was like.

3)._______________________________(explain) many times, the maths problem was still difficult to understand.

翻译：1. 完成作业后，男孩去玩电脑游戏。

2. 多年没回村子了，他发现村子变化很大。