1. hasn't been opened
-> for ages -> thì HTHT
2. has already been sentenced
-> already -> thì HTHT
3. has just been caused
-> just -> thì HTHT
4. is being cut
-> now -> thì HTTD
5. was sent
-> hành động đã xảy ra và kết thúc trong qk -> thì QKĐ
6. were made
-> như câu 5
7. was founded
-> ago -> thì QKĐ
8. were sung
-> last week -> thì QKĐ
9. have been rescued
-> recently -> thì HTHT
10. Were you born
-> như câu 5
11. was your house built
-> như câu 5
12. was witnessed
-> last week -> thì QKĐ
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@Câu bị động:
- HTHT: S + have/has been + P2 + (by O)
- HTTD: S + am/is/are + being + P2 + (by O)
- QKĐ: S + was/were + P2 + (by O)