How did the physical environment of river valleys negatively impact ancient civilizations? The land was attractive to outside invaders who wished to conquer the land. Rivers prevented the people from moving because they could not cross them. Occasionally, extreme flooding caused great damage and killed many people. Silt in the rivers made the water dirty and possibly unsafe for people to drink.

Astate's representation in the u. s. senate is based on a) equal representation. b) the state's population. c) the state's electoral votes. d) the size of their major cities. this independent regulatory agency was created in 1974 to oversee and regulate the financing of political campaigns in the united states. a) warren cthis independent regulatory agency was created in 1974 to oversee and regulate the financing of political campaigns in the united states. a) warren commission (wc) b) federal election commission (fec) c) equal opportunity commission (eoc) d) securities and exchange commission (sec)