Since the 1970s, archaeological sites in China's Yangtze River region have yielded evidence of sophisticated rice-farming societies that predate signs of rice cultivation elsewhere in East Asia by a thousand years. Before this evidence was discovered, it had generally been assumed that rice farming began farther to the south. This scenario was based both on the geographic range of wild or free-living rice, which was not thought to extend as far north as the Yangtze, and on archaeological records of very early domestic rice from Southeast Asia and India (now known to be not so old as first reported). Proponents of the southern-origin theory point out that early rice-farming societies along the Yangtze were already highly developed and that evidence for the first stage of rice cultivation is missing. They argue that the first hunter-gatherers to develop rice agriculture must have done so in this southern zone, within the apparent present-day geographic range of wild rice.
　　Yet while most stands of wild rice reported in a 1984 survey were concentrated to the south of the Yangtze drainage, two northern outlier populations were also discovered in provinces along the middle and lower Yangtze, evidence that the Yangtze wetlands may fall within both the present-day and the historical geographic ranges of rice's wild ancestor
　　1. Which of the following, if true, would most clearly undermine the conclusion that the author makes based on the 1984 survey?
　　Areas south of the Yangtze basin currently have less wild-rice habitat than they once did.
　　Surveys since 1984 have shown wild rice populations along the upper Yangtze as well as along the middle and lower Yangtze.
　　The populations of wild rice along the Yangtze represent strains of wild rice that migrated to the north relatively recently.
　　Early rice-farming societies along the Yangtze were not as highly developed as archaeologists once thought.
　　In East Asia, the historical geographic range of wild rice was more extensive than the present-day geographic range is.

　　2. Based on the passage, skeptics of the idea that rice cultivation began in the Yangtze River region can point to which of the following for support?
　　Lack of evidence supporting the existence of rice-farming societies along the Yangtze at an early date
　　Lack of evidence regarding the initial stages of rice cultivation in the Yangtze region
　　Recent discoveries pertaining to the historical geographic range of rice's wild ancestor
　　New information regarding the dates of very early domestic rice from Southeast Asia
　　New theories pertaining to how hunter-gatherers first developed rice agriculture in East Asia

　　3. Which of the following can be inferred from the passage about the “southern-origin theory”?
　　The theory is based on an unconventional understanding of how hunter-gatherers first developed rice agriculture.
　　The theory fails to take into account the apparent fact that evidence for the first stage of rice cultivation in the north is missing.
　　The theory was developed primarily in response to a 1984 survey of wild rice's geographic range.
　　Reassessment of the dates of some archaeological evidence has undermined support for the theory.
　　Evidence of sophisticated rice-farming societies in the Yangtze region provides support for the theory.

　　答案：CBD