18.The mailman had already delivered the mail
The mail had already been delivered by the mailman.
19.He used to borrow my pen
My pen used to be borrowed by him.
20.He had to finish his work on time
His work had to be finished on time.
21.You needn't do all the homework
All the homework needn't be done by you.
22.You ought to tell him early
He ought to be told early by you.
23.They don't use the room very often
The room isn't used very often by them.
24.They must widen the road to school this year
The road to school must be widened this year.
25.Have you done your homework?
Has your homework been done by you?