World War 1 by Matthew

3. - A type of airship used for reconnaissance and bombing.
7. - The country that joined the war in 1917, tipping the balance.
11. - The assassination that sparked the war took place in this city.
13. - The final German offensive of the war in 1918.
14. - The Ottoman campaign against Armenians during the war.
16. - The battle that marked the first major use of tanks.
18. - Germany's plan to avoid a two-front war by invading Belgium and France.
19. - The treaty that ended the war in 1919.
20. - A deadly chemical weapon first used during the war.

1. - The 1916 battle fought over a fortified town in France.
2. - Secret message from Germany to Mexico, proposing an alliance.
4. - A famous poem written about a battlefield in Belgium.
5. - Germany's allies during the war were collectively called this.
6. - The Central Powers included Germany, Austria-Hungary, the Ottoman Empire, and this country.
8. - The type of warfare characterized by long, narrow ditches.
9. - The main river crossed during the Battle of the Marne.
10. - The American president during the war.
12. - British ocean liner sunk by a German U-boat in 1915.
15. - The first country to declare war in WWI.
17. - The nickname given to American soldiers in the war.