Change the sentences into the passive voice:
1. Who often do the house work?
-> Who is the housework often done ?
2. When does she sell her old car?
-> When is her old car sold ?
3. How many books do they buy?
-> How many books were they bought
4. Does Mrs Hoa visit you once a month?
-> Was you visited by Mrs Hoa once a month ?
5. I don't write to Minh.
-> Minh isn't written by me