$\text{1. didn't use to be}$
$\text{2. used to travel}$
$\text{3. used to take}$
$\text{4. used to ride}$
$\text{5. used to be}$
$\text{6. used to be}$
$\text{7. used to make}$
$\text{8. used to be}$
$\text{9. used to be}$
$\text{10. used to be}$
$\text{11. didn't use to find}$
$\text{12. used to take}$
Áp dụng cấu trúc used to + V didn' t use to + V