The ancient civilizations of mesopotamia and egypt had which of the following in common?

The ancient civilizations of Mesopotamia and Egypt were both facilitated by rivers that ran in their midst. The Euphrates, Tigris, and the Nile deposited silt along riverbanks which made the adjoining land extremely fertile. This led to the development of cities like Ur and Eriku in Mesopotamia, and Thebes in ancient Egypt. In Egypt, the Nile served as a means of transportation and also provided protection from enemies because its marshy deltas made invasion almost impossible.

the correct labels are as follows:

a: yellow river

b: himalayan mountains

c: north china plain

d: taklimakan desert

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.