4) 1. Were you watching
2. suddenly heard
3. wasn't waiting
4. was talking
5. waved
5) 1. saw
2. asked
3. was listening
4. didn't hear
5. picked up
6. put
7. got
8. took
9. was looking
10. was searching
6) 1. didn't use to go
2. didn't use to
3. did you do
4. used to go
5. didn't watch
4) 1. Were you watching
2. suddenly heard
3. wasn't waiting
4. was talking
5. waved
5) 1. saw
2. asked
3. was listening
4. didn't hear
5. picked up
6. put
7. got
8. took
9. was looking
10. was searching
6) 1. didn't use to go
2. didn't use to
3. did you do
4. used to go
5. didn't watch