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1. She had already finished her homework by the time her parents got home.

2. He had been studying for the exam for weeks, so he felt confident when he took it.

3. They had visited every museum in the city before they left for their vacation.

4. The company had received numerous complaints about the product before they recalled it.

5. She had learned to play the piano before she even started school.

6. He had written several articles for the newspaper before he was promoted to editor.

7. They had traveled to every continent before they retired.

8. The team had won three championships before they disbanded.

9. She had completed her degree before she started looking for a job.

10. He had invested his money wisely, so he had a comfortable retirement.