She _______ (study) English for 5 years before she visited Canada.
had been studying
My sister _______ (do) the laundry since early morning.
had been doing
Olivia and Victor _______ (chat) via Skype for an hour when the connection broke.
had been chatting
She _______ (sleep) for 3 hours when we woke her up.
had been sleeping
I _______ just _______ (finish) writing a letter when the door bell rang.
I had just finished writing a letter when the door bell rang.
When the hunters arrived he ____ already _______ (kill) the animal.
had already killed
We _______ (cook) all day for the party and by 7 o'clock we still weren't ready.
had been cooking
I knew that our parents _______ (grow) melons in their greenhouse since they bought the house.
had been growing
Bob _______ (eat up) all the muffins by lunchtime.
had eaten up
Julia wanted to sit down as she _______ (stand) at work all day long.
had been standing