17. Liz didn't buy any souvernirs in Ho Chi Minh city.
=> Did Liz buy any souvernirs in Ho Chi Minh city ?
18. I wasn't very tired after the trip.
=> Was you very tired after the trip ?
19. They aren't watching my father's new motorbike.
=> Are they watching your father's new motorbike ?
20. We didn't visit Cham Temples last month.
=> Did you visit Cham Temples last month ?
21. Trung's brother doesn't go on holiday in Ha Long Bay every summer.
=> Does Trung's brother go on holiday in Ha Long Bay every summer ?
22. They won't take their soon to the zoo next weekend.
=> Will they take their soon to the zoo next weekend ?
23. My parents don't live in the countryside.
=> Do your parents live in the countryside ?
24. Tom did't give me any American stamps five years ago.
=> Did Tom give you any American stamps fives years ago ?
25. Mrs. Oanh isn't our new literature teacher.
=> Is Mrs. Oanh their literature teacher ?
26. There wasn't a toy store next to the museum.
=> Was there a toy store next to the museum ?