Can you check if I made any mistake please? :)

C. CHOOSE THE PAST PERFECT, OR THE PAST PERFECT CONTINUOUS
1. When we arrived the film _____________had already started___________________ (start).
2. She ______________had been working__________________ (work) in that company for
twenty years when she was made redundant.
3. I felt ill because I ________________had drunk________________ (drink) six cups of
coffee.
4. I _______________had been studying_________________ (study) all day, so I was tired.
5. How long ________________had you been living________________ (you / live) in London
when your daughter was born?
6. When I arrived at the airport I realised I
______________had forgotten__________________ (forget) my passport.
7. I ______________had broken__________________ (break) my ankle, so I couldn’t go
skiing last year.
8. She _________________had been studying_______________ (study) English for three years
when she took the exam.