5. Which weapon caused 1.3 million casualties? * ww1

World War I ends with 1.3 million casualties caused by chemical weapons, including 90,000 to 100,000 fatalities, primarily from phosgene. 1925 The Geneva Protocol is adopted by the League of Nations. The treaty bans the use of chemical and biological agents in war but does not prohibit the development, production, or stockpiling of such weapons.

Explanation:

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answer; the basal forebrain;