Как можно защитить горные дороги от снежных лавин?

1 Past Simple - said, Future in the Past (passive) - would be called
2 Past Simple - said, Past Simple - couldn't make
3 Past Simple - could say, Future in the Past - would be
4 Past Simple - did not know, Past Perfect - had got
5 Past Simple -  was sure, Past Simple - did not know, Past Perfect -  had happened
6 Past Simple - couldn't believe, Past Simple - knew
7 Past Simple - said, Past Simple - had, Future in the Past - would ask
8 Past Simple - said, Future in the Past - would take
9 Past Simple - said, Future in the Past - should travel
10 Past Simple - couldn't believe, Past Perfect - had invented
11 Present Simple - thinks, Future Simple - will finish