I.

1.on

2.for

3.at

4.in

5.at

6.on

7.on; in

8.to;at

II.

1.These flower trees are watered by my father every morning

2.Fiona was invited to John's birthday party last night

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

4.Our teeth should be cleaned twice a day

5.We are given a free period this Saturday to prepare the festival by our teacher

III.

1.Someone caused another accident on this road this afternoon.

2.Tom's parents bought him a new bike yesterday afternoon

3.The manager didn't phone the secretary this morning

4.Did Mary buy this beautiful dress?

IV.

1.was built

2.were erected

3.is surrounded

4.is considered

5.is located

6.was discovered

7.is visited

8.was built

9.is located

10.are sold