These houses were built last year ( пассив в прошед.)
Many new houses are built in our country. (пассив в наст.)
Butter was bought yesterday. (пассив в прош.)
Butter is bought in this shop. (пассив в наст)
Сhees is made form milk. (пассив в наст)
This soup was cooked yesterday evening. (пассив в прошед.)