Answer: The Cambrian Period
Explanation:
Answer:
Due the probability of a German counterattack, the Westen Allies engaged into an initial defensive against any likely invasion by creating a system of fortresses on the frontier but also leaving gaps to be able to canalize any German attack; one of those offensives around 1914 in WWI was called <em>"The First Battle of the Marne"</em>, resulted in a victory for the Allies.
