1. an important experiment is being carried out by the scientists.
2. cheese is made from milk.
3. was the first plane built by W. brothers in 1903?.
4. the ziooer was invented by W.L.J in 1893.
5. the ballpoint pens have been used for many years.
6. a book will be published on space travel next month.
7. when I came, the computer was being repaired.
8. romeo and Juliet was written by Shakespeare in 1592.
9. these rooms are going to repain by Viet tomorrow.
10. this kind of paper is not produced by our factory.

Thì HTĐ : S + V s / es <---> S + be + V3 ( by O )

- Thì QKĐ : S + V ed <---> S + was / were + V3 ( by O )

- Thì HTTD : S + be + V-ing <--> S + am,is,are + being + V3 ( by O )

- Thì QKTD : S + was / were + V-ing <---> S + was / were + being + V3 ( by O )

- Thì HTHT : S + have / has + V3 <---> S + have / has + been + V3 ( by O )

- Thì TLĐ : S + will + V <---> S + will be + V3 ( by O )