Ответ:
1) I had finished my work by seven o'clock.
2) He thought that he had lost the money.
3) Ann told me that she had seen an interesting film.
4) When I came home, mother already had already cooked dinner.
5) When father returned from work, we hadn't done our lessons yet.
6) When the teacher entered the classroom, the pupils already had already done their tests.
7) Kate showed me the book which she had bought the day before.
8) The teacher understood that Lena hadn't done her homework.
Объяснение:
Удачи!