What did germany do that started ww1?

Well, Germany is not usually thought to have started it, rather a Serbian rebel, Austrian ultimatum to Serbia  to catch this rebel, Serbia's refusal to let Austria enter their country and Russian support of Serbia.

After all this, Austria asked Germany to support them, and Germany did, knowing that this means fighting against the powerful Russia.

So Germany's agreement to the ongoing war turned it into a bigger conflict.

To solve their problems, mesopotamians used irrigation, a way of supplying water to an area of land. to irrigate their land, they dug out large storafe basins to hold water supplies these ditches brought water to the feilds. to protect their feilds from flooding, farmers built up the banks of the tigris and euphrates.hope ths !