Trenches were dug in a zigzag pattern so that if an enemy entered the trench, he could not fire straight down the line. ... The main trench lines were connected by communicating trenches, allowing for the movement of messages, supplies, and soldiers and were lined with barbed wire.
It <span>laid the foundations for the beginning of a modern global economy</span>
It picked seeds out of cotton and helped the people sew
I think the answer is the United States
