45. Mr. Kent hasn’t washed his car for ages. 46. An earthquake has destroyed the whole town. 47. An English expert is training our national football team. 48. Ben and John are painting the fence. 49. When did they open that hospital? 50. Why do farmers keep grass in the pasture? 51. A lion killed Mary’s dog last week.

`45.` His car hasn't been washed by Mr. Kent for ages.

`46.` The whole town has been destroyed by an earthquake.

`48.` Our national football team is being trained by an English expert.

`49.` When was that hospital opened (bt them)?

`50.` Why is grass kept in the pasture by farmer?

`-` keep - kept - kept: giữ

`51.` Mary’s dog was killed by a lion last week.

______________________________________________________

`-` Bị động của thì hiện tại hoàn thành:

$(+)$ S + have/ has + been + V(pp) + (by O)

$(-)$ S + have/ has + not + been + V(pp) + (by O)

`-` Bị động của thì hiện tại đơn:

$(+)$ S + am/ is/ are + V(pp) + (by O)

$(?)$ Am/ Is/ Are + S + V(pp) + (by O)?

`-` Bị động của thì quá khứ đơn:

$(+)$ S + was/ were + V(pp) + (by O)

$(?)$ Was/ Were + S + V(pp) + (by O)?

`-` Bị động của thì hiện tại tiếp diễn:
$(+)$ S + am/is/are + being + V(pp) + (by O)