Первое задание
1. Before I took a bus to school I had already eaten my breakfast.
2. Before I came to this class I hadn't studied English yet.
3. Before I left the house I had already turned off the lights.
4. Before I had a test I had already studied all the new words.
Второе задание
1. before
2. after
3. before
4. after
Третье задание
had already started, had noticed, felt, had looked for her, had met, dissappeared, thought, had decided, waited, went, hadn't seen, had touched, raised, had never forgotten, was, had found