Past Perfect vs Past Simple

We had already eaten when Mike _____ (come) home.

Last year Rob _____ (pass) all his exams.

When I ____ (get) to the airport, I discovered I had forgotten my passport.

I went to the library, then I _____ (buy) some milk and went home.

I opened my bag to find that I ______ (leave) my credit card at home.

We got home to find that someone ______ (break) into the house.

She _____ (sit) down after she'd switched on the TV.

I turned off the radio when the news bulletin _____ (finish).

Ana hadn’t studied English before she _____ (come) to our

school.

I didn't say a word until she _____ (stop) talking.