The key answer of exercise 1

a)

1. usually see
2. used to play
3. don't usually go
4. normally wears
5. Did you use to have
6. stayed
7. never used to watch
8. went cycling

b)

1. did you use to live
2. ✓
3. ✓
4. doesn't usually wear
5. ✓
6. usually walk
7. ✓
8. Do yo usually / normally
9. went
10. ✓

c)

1. used to wear
2. usually give
3. usually call
4. used to go
5. used to eat out
6. don't usually work
7. used to be
8. didn't use to like