I believe the answer is The First Anglo Chinese War.
Please tell me if I am wrong.
Most soldiers started to use gas bombs
Answer:
Nuremberg Trials
Explanation:
"the Nuremberg trials were a series of 13 trials carried out in Nuremberg, Germany, between 1945 and 1949. The defendants, who included Nazi Party officials and high-ranking military officers along with German industrialists, lawyers and doctors, were indicted on such charges as crimes against peace and crimes against humanity."
Workers were housed in areas surrounding factories or mines, most families lived in a one bedroom apartment with 6-9 people, living conditions were poor, disease spread easily, food was provided by employers 2 times a day, living expectancy was 17 years old.
Neanderthals and I think homo erectus