The teacher told us to do morning exercises .
The car to be bought is for his sister.
She pretended to be reading when the teacher came into the classroom.
The thief is said to have escaped.
The thief is said to have been arrested.
She is said to have been working in the factory over the last 20 years.
2、 动名词
③完成式:having done(表示主动和完成)
④完成被动式:having been done(表示被动和完成)