Which of the following groups of 3 terms represent common characteristics of civilizations? a
Permanent settlements (cities/towns), government & infrastructure, religious/philosophical belief system.
b
Infrastructure, monotheism, hunting & gathering.
c
A rival civilization, written language, social classes.
d
A police/military force, stable economy, technology.

Afarmer who is grown corn for the past five years notices in the sixth year that the his harvest is significantly smaller, despite an increase in labor on the farm. the following year, the harvest continue to decline. which of the following explanations most plausibly accounts for the reduction in corn yield? a) soil degradation b) desalinization c) better irrigationd) terracing