Ответ:

1 When the police arrived, the car had gone.

2 George finished doing his homework at eight o'clock.

3 When she got to the shop, it had closed.

4 The train had left when he came to the station.

5 We had eaten everything by the time he arrived at the party.

6 I knew that he hadn't learnt the poem.

7 When they left the beach, the rain had already started.

8 Arthur didn't know that we had already arrived.

9 When I came I saw that mother had cooked dinner.

10 My friend had studied English before he entered the institute.

11 The car had gone when I looked into the street .

Объяснение: