Odpowiedź:
1 The doctors had found a cure for the mystery illness, so I wasn't worry about it.
2 When the new problem was found, the patient had already been released from hospital.
3 The police officer had saved the woman's life before the ambulance arrived.
4 I couldn't pay for my medicine because I had left my wallet at home.
5 Because Michael had begun to feel ill, he couldn't concentrate on the lecture.
6 tego nie jestem do końca pewna
albo
By the time I answered all of my text messages my thumb had hurt.
albo
By the time my thumb hurt I had answered all of my text messages.
chociaż najbardziej sensowna to bałaby taka opcja:
By the time I answered all of my text messages my thumb had started to hurt. (ale w zdaniach bazowych nie ma czasownika start, więc nie wiem, czy tak można sobie bezkarnie dodawać)
