Answer/Explanation:
An irrigation system represents a stable food supply because it is how they controlled water to be able to plant crops. A second most important artifact that is in the category of stable food supply is the plow. Agriculture produced enough food that people became free to pursue interests other than worrying about what they were going to eat that day.
As well as providing the alliance with its name, the geographical position of the German and Austro-Hungarian empires also gave the Central Powers at least one very important strategic advantage over the Allies they were fighting. It was much easier for the Germans and Austro-Hungarians to move troops, equipment and supplies from one battle front to another because they could do much of this on their domestic railway networks.
German soldiers exit trench
German soldiers exit trench
For example, the Germans could move 10 infantry divisions from the Eastern Front to the Western Front via a relatively straightforward journey across Germany. It was no more difficult for the Austro-Hungarians to move five infantry divisions from the Eastern Front to the Italian Front, or to the Salonika Front in the Balkans.