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3 was, were,  realized, didn't have

4 reminded

5 decided

6 drove, rode

7 were swimming, visited

8 decided

9 were waiting, bought, helped

10 saw

11 ran

12 was sleeping, closed

13 decided

14 were trekking

15 visited

15 was

* в тексте задания есть ошибки: Nastya were really afraid (должно быть Nastya got frightened/got scared) и слово buy (купить) написано неверно