Здесь нужно сверху, над глагольными формами, указать последовательность событий с цифр 1 и 2 (1 - что случилось раньше, 2 - что произошло потом).
2 1
1. By the time I left the building everyone had gone home. (то есть, сначала все ушли, потом я)
2 1
2. I looked in the garden, but they had already gone to work.
1 2
3. They had cleaned everything up by the time their parents returned.
1 2
4. I had already taken three aspirins, but they didn't help.
2 1
5. I wanted to have a bath, but someone had used all the hot water.
1 2
6. We had made our plans carefully and won the prize.
1. This letter was received by us after his departure.
2. Have you been ever attacked by dogs?
3. Honey is gathered from flowers by bees.
4. The ship was driven against a rock by the storm.
5. Who was the circulation of blood discovered by?
6. Delicious fruit ice cream is being sold by them there now.
7. The way out of the wood was shown to us by an old man.
8. She was offered some interesting work by them.
9. New medicine was prescribed to her by the doctor.
10. He is often spoken of by them.
11. This funny animal was laughed at by everybody.
12. You have been looked for by us the whole morning.
13. Strict discipline will be insisted on by us.
14. Three foreign languages are taught at this school by them.