U-boats were used primarily to gather information about enemy movements by tracking warships.
protect the German coast from attack by Allied ships and submarines.
resupply troops with guns, ammunition, and food via sea rather than land.
target Allied shipments on passenger ships, warships, and merchant ships.

the process is called revolution because it was a process of great economic-social transformations that began in england in the xviii century.

the industrial mode of production spread throughout much of the northern hemisphere throughout the xix and early xx centuries.

the effect of this revolution was the distance between the countries, with respect to economic and political power.   after all, not all industrialized at the same time, remaining in the condition of suppliers of raw materials and agricultural products to the industrialized countries.

these differences mark to this day the nations of the world that are divided between developed and developing countries. one way to measure whether a country is advanced is to assess how industrialized it is.

stick up my a**

portugal, spain, france, netherlands, and great britain