World War 1 Crossword Puzzle

QUESTIONS LIST: submarines : german u-boats, colonies : germany lost its _ in africa and asia, armistice : agreement to stop shooting, italy : this country switched sides during the war, tank : new weapon armored vehicle, france : triple entente - england, _ , and russia, somme : battle of the _ - british lost 600,000, germans lost 500,000. tanks were used for the first time, guilt : war _ clause - germany had to admit wwi was their fault, lorraine : germany had to give alsace- _ to france after the war, trench : wwi was the first time soldiers fought mainly in a _ , zipper : new clothes fastening that made us army uniforms quicker to do up, plastic : this type of surgery owes a lot of its development to ww1, princip : gavrilo _ assassinated franz ferdinand, firestep : soldiers stood on this to fire across the their guns, periscope : used to see over the top of the trench, helmet : this item led to an increase in head injuries, pilates : this was used to keep the strength of the soldiers up when living in the trenches, shellshock : now known as ptsd, this severe mental health condition was caused by the extreme horrors of warfare