chuyển sang bị động thì hiện tại hoàn thành :
1. they have not used this machine for ages.

=>This machine hasn't been used for ages
2. peter has sung this song.

=>This song has been sung by Peter
3. she has eaten all the eggs.

=>All the eggs have been eaten
4. famous engineers have designed the aircraft.

=>The aircraft has been designed by famous engineers
5. Have several people just seen the accidents?

=>Have the accidents just been seen by several people?
6. The news has surprised me.

=>I have been surprised by the news
7. John has broken my watch.

=>My watch has been broken by John