14. This is the second time I have been taken to the zoo by my dad
BĐ thì HTHT: S have/has (not) been PII O (by sb)
15. We have been taught French by Mr.Smith for two years
16. The children weren't looked after properly
BĐ thì QKĐ: S was/were (not) PII O (by sb)
17. The dog wasn't looked after properly
18. Were the children looked after properly?
19. This street wasn't swept last week
20. The letters are typed in the office every morning by Mary
BĐ thì HTĐ: S am/is/are (not) PII O (by sb)
21. My computer was taken yesterday
22. My computer was stolen yesterday
23. His essay had been finished by Tom before 10 pm last night
BĐ thì HTHT: S had (not) been PII O (by sb)
24. You will be helped tomorrow by his father
BĐ thì TLĐ: S will be PII O (by sb)