Answer:
Indus river (India): Harappa And the city of Mohenjo-daro
Nile river (Egypt): Ancient egyptian pryramid structures, obelisks, System of mathmatics, Medicine development, etc.
Huang he (China): The great wall of china build, development of budda religion, growing rice products.
Tigris-Euphrates (Mesopotamia): The wheel, plow tool, and cut canals and river connections.
<span>It forced the Germans to fight the war on two fronts.
</span>
The transcontinental railroad transformed the west because it made the idea of manifest destiny so much easier to achieve. The railroads also gave access to many trade spots, which in result connected them all, making the economy of America BOOM.
I think b is the one that is not true