The World One: Trench Warfare Crossword Puzzle contains two versions of the puzzle for differentiation. One version has a word bank, the other version does not. The answer key is also included. This puzzle is great as a vocabulary builder, review, or enrichment learning activity for any World War One unit. This puzzle includes 29 vocabulary terms and expressions such as: machine gun, howitzer, grenade, no man's land, pickelhaub, barbed wire, mustard gas, chlorine gas, etc.