Ответ:
1. Brendahad worked /had been working here for a year before she left to go to the university.
2. He was driving to work at this time yesterday morning.
3. I had already eaten breakfast by the time the others woke up.
4. It had been raining for two days when suddenly the sun came out.
5. They had already seen the film twice at the cinema when she rented
it on video.
6. The teacher taught / was teaching the students how to use past tenses yesterday.
7. The cousins went to the Crimea for their holidays last summer.
8. They were playing tennis on the sports ground when the weather
changed.
9. After I had finished my essay, I left the library.
10. Everybody was dancing in the hall when electricity suddenly went off.
11. By the time he found what he wanted he had spent all the money.
12. A fire broke out in a residence hall where a lot of students were staying.
13. She paid for the furniture last month.
14. When we arrived at the cinema the film had (already begun.
15. I saw her at the post office. She was filing in some forms.
16. At school he did well at mathematics.
Объяснение: