1 - They have published her new book recently.
The new book has been published recently by them.
2 - The town council has just opened our local museum.
Our local museum has just been opened by the town council.
3 - Their house looks very neat after they have painted it.
Their house has been painted by them.
4 - The room looks nice. Somebody has cleaned it.
The room has been cleaned by somebody.
5 - My dress is clean. Someone has washed it.
My drees has been washed by someone.
6 - Dinner is ready and hot. Someone has just cooked it.
The dinner has just been cooked by someone.
7 - They have opened a new theatre in the city.
A new theatre has been opened in the city by them.
8 - There are no letters on the table. Somebody has posted them.
The letters have been posted by somebody.