10. Minh is going to buy a new bicycle tomorrow.
=> A new bicycle is going to be bought by Minh tomorrow.
11.We learned English yesterday.
=> English was learned yesterday (by us).
12.They will buy a new doll next week.
=> A new doll will be bought next weeks (by them).
13. My father was watching TV at 8 o'clock last night.
=> TV was being watched by my father at 8 o'clock last night.