One important difference between the nile river valley and mesopotamia was

the Nile flooded at the same time every year as opposed to the unpredictable flooding of the Tigris and Euphrates Rivers. The predictability of the flooding allowed agriculture to become a mainstay in Egyptian cultures that made their homes along the banks of the Nile river. The predictable floods brought fertile soils which signaled the start of the growing season each year.  

Explanation:

soviet influence spread across eastern europe sharply during and after wwii. the soviet armies liberated the countries in eastern europe and occupied them from the germans as they were forced to retreat towards germany.

d.

the northwest territory became the most densely populated area in the u.s.