В некоторых пунктах я добавил второй вариант ответа, т. к. не уверен в их правильности из-за недостка информации в предложениях. (отметил их скобочками)
1. were; would leave
2. lived; would visit
3. get; will go
4. lived; would gather
5. returned; would watch
6. knew (have known); would try (would have tried)?
7. came; would be
8. buys (bought); will have (would have)?
9. receive (received); won't worry (wouldn't worry)?
10. don't work; will fail
11. snows; will go
12. phones; talk
13. would have driven; had asked
14. would have helped (would help); hadn't been (wasn't)
15. wouldn't be; arrived
16. didn't change; would take
17. will write; get
18. didn't buy; wouldn't make
19. listened; would understand
20. would have found (would find); had looked (looked)?
