Answer:
Chemicals and Poison Gas was used!
Step-by-step explanation:
World War is referred to as the first scientific war,as it used chemical,such as poison gas to kill people."It is estimated that as many as 85% of the 91,000 gas deaths in WWI were a result of phosgene or the related agent, diphosgene (trichloromethane chloroformate). The most commonly used gas in WWI was 'mustard gas' [bis(2-chloroethyl) sulfide]",(kumc.eu)