Question

like some liquid the heavy-coloured vapour poured relentlessly into the trenches, filled them, and passed on. for a few seconds nothing happened; the sweet-smelling stuff merely tickled their nostrils; they failed to realize the danger. then, with inconceivable rapidity, the gas worked, and blind panic spread. hundreds, after a dreadful fight for air, became unconscious and died where they lay – a death of hideous torture, with the frothing bubbles gurgling in their throats and the foul liquid welling up in their lungs. with blackened faces and twisted limbs one by one they drowned –only that which drowned them came from inside and not from out. –british eyewitness on the western front, 1915 the soldiers who were struck by the gas attack in this passage experienced eye irritation. skin blisters. sudden death. sleepiness.

Explanation:

The passage describes soldiers exposed to a gas attack. Phrases like "became unconscious and died where they lay", "frothing bubbles gurgling in their throats", and "drowned... from inside" indicate a rapid, lethal effect. Eye irritation (mild, not matching severe death), skin blisters (not mentioned), and sleepiness (contradicts panic and death) are inconsistent. Sudden death aligns with the rapid onset of unconsciousness and fatal respiratory distress.

Answer:

sudden death.