Technology Puzzle

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Across
  1. 3. known for its accuracy and reliability
  2. 6. underwater weapons
  3. 7. caused severe repiratory problems and damage to the eyes and skin
  4. 9. a type of gun providing high rate of fire
Down
  1. 1. air combat
  2. 2. known for blistering effects
  3. 4. military tactic where opposing forces dig into the ground
  4. 5. could fly at high altitudes and cover long distances, making them useful for strategic bombings
  5. 8. used for trenches