II.

1.at  2.on  3.in  4.on  5.at  6.on  7.in  8.in  9.in  10.on

III

1.on  2.on  3.on/at  4.at  5.in  6.on  7.at  8.at/in  9.on  10.in  11.on  12.in

II

1. At

2. On

3. On

4. O

5. O

6. O

7. O

8. In

9. O

10. In

III

1. On

2. In

3. On...at

4. In

5. On

6. On

7. At

8. At..in

9. On

10. In

11. Before

12. After

VI

1. Having dinner while they were listening to the radio

2. Started when she was sleeping

3. Were you doing when it began to rain?

4. He was ploughing the field, the farmer started whistling

5. Were they doing when you came

6. Happening when she came

7. Came in when she was reading a book

8. Erupted when they were working in the field

9. Hit the town when the ship was leaving the harbor

10. On the head when he was going to his car