36 Two department stores have been built by they
-> câu bị động thì HTHT
-> ta có cấu trúc : S + have / has + VPII _+ by + O
37 i haven't seen her for 10 years
-> thì HTHT kết hợp for
-> S + have / has + VPII + for + 1 khoảng thời gian
38 tuan used to go fishing
-> often = used to = thường làm
-> used to + V nguyên mẫu