Past Perfect Progressive

Abbina le forme ING dei verbi a destra con le frasi a sinistra per completarle in modo corretto
They had been _____ very hard for their exam. They were exhausted.
How long had you been _____ when you felt asleep?
Had you been _____ when the alarm clock rang?
I had been _____ for her since 8 o'clock. I was very upset!
I'd been _____ a book when Claire called me on the phone.
She had been _____ with her boss since this morning. She was very tired.