Answer:
Austrian - Serbia: Many of the demands were so extreme that Serbia had no choice but to reject some of them; result: Austria-Hungary declared was on Serbia.
Germany - Russia: The German government warned Russia that it must stop its mobilization; result: Russia refused, Germany declared war on Russia
Germany - France: Under the Schlieffen Plan, Germany could not go to war against Russia; result: Germany declared war on France
Germany - Belgium: Germany demanded the right of German troops to pass through Belgium, even though it was a neutral nation.
Great Britain - Germany: Britain was upset that Germany violated Belgian neutrality and concerned about maintaining its own world power.; result: Great Britain declared war on Germany.
All of the great nations were now at war.
Explanation: