What event triggered the alliance system which led to the first world war?

The assassination of Archduke Ferdinand sparked the beginning of WWI and because of that, Austria declared war on Serbia. Russia was an ally of Serbia and because of Austria declaring war on Serbia, Russia mobilized its forces. Then Germany, being an ally of Austria-Hungary, declared war on Russia and France. Germany had a plan to invade France through Belgium. Because of Britain being an ally of Belgium, Britain declared war on Germany.

This would be an open primary. a closed primary people can vote only prior to election day if the party if they are registered. independent voters can not participate. there is not a wide-open primary, but there is a semi-open primary.