GRE Reading Comprehension: OG/PP2-GRE阅读OG/PP2 - 544841C4AR07937VP

The fact that "adjacent agricultural fields can produce significantly different yields" is offered as evidence of the A. unpredictability of the climate and environment of the southwestern United States B. difficulty of producing a consistent food supply for a large population in the Western Pueblo region C. lack of water and land suitable for cultivation in central Arizona D. local climatic variation in the environment of the southwestern United States E. high-frequency environmental processes at work in the southwestern United States