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.

Answer (a) the itcz comes overhead for part of the year; i believe this is correct,plz check first; ///

Humans have survived and thrived in mexico city by using technology to create greater access to land. when the spanish conquered the aztec capital, tenochtitlan, in the 16th century, they built mexico city by draining the lakes and filling in the lake water to create more arable land for agriculture. this technique of land reclamation has continued to be fundamental to human civilization in mexico city.