I
1. slept
2. were
3. Did you drink
4. wasn't
5. did
II
1. hasn't finished
2. haven't taken
3. Has he sold
4. hasn't been
5. Have, left
III
1. went
2. have just returned
3. have never seen
4. didn't work
5. didn't move
IV
1. a
2. c
3. c
4. a
5. b
6. b
7. c
8. b
9. b
10. c