1. She *had been studying* for hours before the exam started. (Dica: ação contínua que aconteceu antes de outra ação no passado)
2. They *had been working* on the project all day when the manager arrived. (Dica: ação prolongada no passado anterior a outra)
3. I *had been waiting* at the bus stop for 30 minutes before it came. (Dica: verbo “wait” no Past Perfect Progressive)
4. He *had been playing* football since morning before it began to rain. (Dica: ação em progresso até um ponto no passado)
5. We *had been living* in Baku for five years before moving to Ganja. (Dica: verbo “live” no Past Perfect Progressive)
6. The children *had been watching* TV when the power went out. (Dica: ação contínua interrompida por outra)
7. You *had been reading* that book before I borrowed it. (Dica: ação duradoura no passado)
8. She *had been cooking* dinner when the guests arrived. (Dica: verbo “cook” no Past Perfect Progressive)
9. They *had been traveling* for days before reaching their destination. (Dica: ação contínua no passado anterior)
10. I *had been thinking* about that idea all morning before deciding. (Dica: verbo “think” no Past Perfect Progressive)

1. Before the meeting, I *had been preparing* the report carefully. (Dica: ação contínua anterior a outra)
2. She *had been practicing* the piano for hours when the recital started. (Dica: verbo “practice” no Past Perfect Progressive)
3. We *had been discussing* the problem for a long time before finding a solution. (Dica: ação em progresso antes de outra)
4. He *had been jogging* every morning before he injured his leg. (Dica: verbo “jog” no Past Perfect Progressive)
5. They *had been cleaning* the house when the guests arrived. (Dica: ação contínua interrompida)
6. I *had been writing* emails all afternoon before the internet stopped working. (Dica: verbo “write” no Past Perfect Progressive)
7. You *had been learning* Azerbaijani for months before your trip. (Dica: ação prolongada antes do passado)
8. She *had been driving* for hours before she took a break. (Dica: verbo “drive” no Past Perfect Progressive)
9. We *had been waiting* for the train when it finally arrived. (Dica: ação contínua antes de outra ação)
10. They *had been playing* chess all evening before dinner was served. (Dica: verbo “play” no Past Perfect Progressive)