I.1 this flower is watered by my father every morning 

2 fiona was invited to his birthday party by john last night

3  the dinner is being prepared in the kitchen by her mother

4 our teeth should be cleaned twice a day

5 the english grammar has been explained by our teachers

6 the accident was caused in this city by some drunk drivers

7 his parents will be visited by tom next month

8 the secretary wasn't phoned by the manager this morning

9 was this beautiful dress bought by mary?

10 these old pictures won't be hung in the living room

11 this factory wasn't built by the german during the second world war

12 this house and these cars are going to be repainted for christmas day by the greens

13 the cat had been fed by ann before she went to the cinema

14 the pollution problems have been discussed by the students since last week

15 has the most valuable painting been stolen in the national museum by the thieves?

16 the new president will be interviewed on TV

17 how many languages are they spoken in canada?

18 are those shoes going to be rapaired?

19 his nose has been broken in the football match 

20 have the above sentences been finished?

III.1 had spoken

2 wouldn't have been

3 had known