1 my father bought this house two years ago
--> This house was bought by my father two years ago
2 we have done these exercise carefully
--> These exercise have been done by us carefully
3 people recycle car tires to mack pipes
--> Car tires are recycled to make pipes.
4 the workers will build a new school in my town
--> A new school will be built in my town
5 franz gruber wrote the christmast carol in the 19 century
--> The christmas carol was written by Fran gruber in 19 century
6 people can reuse milk bottles for thirty times
--> Milk bittles can be reused for thirty times.
7 people speak english in the world
--> English is spoken in the world.
8 the boy has just broken the classroom window
--> The classroom window has just been broken by the boy.