Đáp án/Giải thích:

21. Mr. Hoang spent half an hour walking to work yesterday. (cấu trúc spend+time+ving)

22. We have lived here for fifteen years. (have+pp)

23. You’d better eat less meat. (had better+động từ nguyên mẫu)

24. You don’t have to set off early. (dont have to+động từ nguyên mẫu)

25. Our house is the oldest one in the living centre. (so sánh nhất)

26. Because he was lazy, he failed the exam. (vì...,kết quả)

27. Hoa’s collection has eight hundred stamps. (... has/have sthing)

28. Do you mind if I smoke in here? (do u mind if+S+Vsimple present)

29. The color of our briedfcases is red. (the color of...is..)

30.  Unless the weather improves, the gardenparty won't take place. (unless=if not)

Học tốt

21 Mr. Hoang spent half an hour going to work yesterday

_ It take + smb + time + to V = S + spend + time + Ving

22 We have lived here for fifteen years

_ S + started/began + Ving/to V = S + have/has + PII 

23 You'd better not eat too much meat.

_ had better not = shouldn't : không nên

24 You don't have to set off early.

_ S + have + to V : phải làm gì

25 Our house is the oldest in the living centre

_ So sánh nhất : adj - ngắn : S + + be + the + adj-est 

26 Because he was lazy, he failed the exam

_ Because + clause(Nguyên nhân)

27 Hoa's collection has eight hundred stamps.

_ There is/are + N = S + has/have + N

28 Do you mind if I smoke in here ?

_ Would you mind if + S + Ved/cột 2 = Do you mind if + S + V(s/es)

29 The color of his briefcase is the same as mine

_  giống : S1 + be + the same as + S2

30 Unless the weather improved,the garden party won't take place.

_ Câu điều kiện loại 1 : If + S + V(s/es), S + will + V