1. The assassination of Franz Ferdinand was a trigger event
2. Germany declared war on Russia and France
3. Soldiers on both sides dug themselves into trenches
4. The Lusitania was a German submarine
5. The British were the first to use poison gas
6. Lloyd George became Prime Minister of Britain in 1916
7. Tanks were first used at the Battle of Verdun
8. America declared war on Germany in 1917
9. Russia signed a peace treaty with Germany after a Revolution
10. Germany signed an armistice in December 1918