IV:
1: This house was bought by my father two years ago.
2: These exercises have been done carefully (by them).
3: Car tires are recycled to make pipes by people
4: A new school will be built by the workers in my town.
5: The Chrismas carol was written by Franz Gruber in tthe 19th century.
6: Milk bottles are reused by people for thirty times.
7: E. is spoken by people in the world.
8: The classroom window has been broken by the boy.
9: His letter was got (by me) this morning.
10: These cars are made by them in Japan.
III:
1:was walking
2:hasn't finished
3:did
4:go