| A | B |
|---|
| trenches | ditches from which to fight |
| Archduke Ferdinand | his assassination was the "spark" that started World War I |
| Arms Race | countries build big armies to be stronger than their neighbors |
| Military Alliance | an agreement between countries to help each other if there is a war |
| World War | a war fought by many countries of the world |
| "No-Man's Land" | the area lying between armies and controlled by neither side |
| airplanes, submarines, tanks | new mobile weapons that changed the way war was fought |
| Lusitania | Americans were killed when this ship was sunk by German U-back |
| League of Nations | all countries of the world should belong to work out problems peacefully |
| President Wilson | he tried to keep the U.S. out of the war |
| Treaty of Versailles | the Big Four worked on this after World War I |
| General John Pershing | he led the U.S. Army in Europe |
| Zimmerman note | this letter was the deciding factor in the U.S. entering the war |
