Тест по английскому Past Tenses помогите решить (по возможности с объяснением, но можно и без)

11. They left after we ______ the program.
a) had discussed+ b) was discussing c) had been discussing d) discussed
12. We were tired as we ________ for more than four hours
a) was walking b) walked c) had been walking+ d) had walked
13. My brother ______ very shy in his childhood.
a) did b) had been c) were d) was+
14. What ________ last Monday?
a) happened+ b) was happening c) had happened d) happens
15. It ______ all day yesterday.
a) rained b) was raining+ c) had rained d) had been rained
16. We ______ great fun at the Halloween party last year.
a) was having b) had+ c) has had d) are having
17. At last he got the opportunity he _______ for so long.
a) had been waiting+ b) waited c) were waiting d) is waiting
18. When I came home my father ______ dinner and was looking through the newspaper.
a) is having b) were having c) had had+ d) had
19. I thought she was the most intellectual woman I __ ever _____.
a) has met b) was meeting c) met d) had met+
20. The room looked beautiful, as she _______ the furniture and the curtains.
a) had changed+ b) changed c) was changing d) is changing
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лучше без