GRE Reading Comprehension: JiJing 352-GRE阅读机经352篇 - 3X47OM67J0W3VOT6J

According to the author, the strategy of rotating crops to eliminate pests has been A. effective in many instances B. used since the earliest days of agriculture C. less effective than genetic manipulation of plants D. most popular in the midwestern United States E. less effective against the northern corn rootworm than against caterpillars