World War I

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Across
  1. 2. This was the deadly area of land between enemy trenches.
  2. 4. The assassination of Archduke Franz Ferdinand was the ____________ that started WWI.
  3. 5. These were the fights between pilots in the air.
  4. 7. These were dug into the ground for soldiers to fight from.
  5. 8. These were German submarines that could strike allied ships without being seen.
  6. 10. Large armored vehicles that were first used in WWI.
Down
  1. 1. These were worn by soldiers in WWI to protect against poison gas.
  2. 3. This was a new weapon that could fire 400-600 bullets a minute.
  3. 6. This term means not picking a side in the war.
  4. 9. This is the acronym for the 4 big causes of the war.