They needed the water from the river to grow their crops, therefore, they began to settle by rivers and their civilization began to grow because they stayed in the same place for agriculture too.
The answer should be:
A. Vietnam War
Answer: A flame thrower.
Explanation:
At the turn of the XIX. in XX. a century in the field of technology and science has made remarkable progress. This also affected the military industry, so some new weapons were used for the first time in the First World War.
Among these weapons was a flame thrower. With a mixture of different chemical substances, these weapons created a massive fire wave. On the battlefield, these weapons burned mercury soldiers, and it is undoubtedly one of the worst ways in which life could be lost during World War I.
