1 happened (action which happened at a specific time in the past)
was chasing (action in progress at a certain time in the past)
stopped (action which interrupted another action in progress in the past)
2 were you doing (action in progress at a certain time in the past)
phoned (action which interrupted another action in progress in the past)
was watching (action in progress at a certain time in the past)
3 Did you see (action which started and finished in the past)
had already finished (past action which finished before another past action)
got (action which happened at a certain time in the past)