26. has changed - came
-> HTHT since QKĐ
27. were talking - started - broke
-> While QKTD, QKĐ
28. had done
-> thì QKHT : S had VPII.
29. has been standing
-> thì HTHTTD: S have/has been Ving
30. have spent - got
-> HTHT since QKĐ
31. was - studied
-> thì QKĐ : S V-ed/C2
32. met - had been working
-> thì HTHTTD: S have/has been Ving
33. had finished - sat
-> After QKHT, QKĐ
34. has
-> Thì HTĐ: S V(s/es).