=>
1. B (QKHT before QKĐ)
2. C (as soon as QKĐ, QKĐ)
3. B (while QKTD, QKĐ)
4. C (by the end of this year -> TLHT)
5. D (be always Ving/need to V: cần làm gì)
6. B (in August -> QKĐ, S V2/ed)
7. A (this afternoon -> QKĐ, S V2/ed)
8. A (since then -> HTHT)
9. D (for 35 years -> HTHTTD)
10. D (since 9 this morning -> HTHTTD)
11. A (thì HTHT -> S have/has V3/ed)
12. B (for months -> HTHT)
13. A (HTHT since QKĐ)
14. A (thì QKĐ, S V2/ed)
15. B (Have/Has S V3/ed before?/last year -> QKĐ, S V2/ed)
16. A (thì TLĐ -> quyết định tại thời điểm nói)
17. C (as planned -> be going to V)
18. C (since -> HTHT/ago -> QKĐ)
19. B (after QKHT, QKĐ)
20. A (when HTĐ, TLĐ)
21. B (As QKTD, QKĐ)
22. B (at midday -> TLTD)
23. C (for you long -> HTHTTD)
24. B (after QKHT, QKĐ)
25. B (When HTĐ, TLTD)
26. C (yesterday at 10:20 pm -> QKTD)
27. A (in the past few years -> HTHT)
28. B (last night -> QKĐ)
29. B (think -> TLĐ)
30. B (By the end of this month -> TLHT)