`1.` Our exercises have been corrected at home by the teacher 

`2.` His mother has been worried by Ali's absence

`3.` Several new schools have been built in our town

`4.` A lion has been killed by Sam since last week

`5.` The job has been finished by me since the factory closed

`6.` That box hasn't been opened for the past hundred years

`7.` Have these letters been mailed by you soon?

`8.` Researches have been carried out on SIDA by scientists for two years

`9.` The poor have been helped in our town

`10.` Mistakes haven't been made 

`11.` She fell into water because she has been pushed 

*Cấu trúc bị động thì hiện tại hoàn thành: 

(+) S + have/ has + been + PP+ (by O)

(- ) S + have/ has + not + been + PP+ (by O)

(? ) Have/ Has + S + been + PP+ (by O)?