1, It took her hours to plant the new flower
cấu trúc it takes SO + time + to V
2, i don't have enough money to buy a train ticket
3, his parents didn't let him go out last night
cấu trúc let SO do ST
4, he started doing this bussiness 20 years ago
start + Ving + khoảng time + ago
5, John began playing football 10 years ago
giải thích giống câu 4
6, have you been working on the car for 3 days ?
7, she has worked in London for 4 months
8, he has investigated the cake for a week