(B)
        Until recently, scrutiny of tree-ring records seemed to establish that a prolongeddry spell called the Great Drought drove the Anasazi Indians to abandon theirmagnificent stone villages on the Colorado Plateau. Groundbreakingclimatological studies have convinced many archacologists, however, that the GreatDrought was not sufficiently austere to coerce the sudden evacuation of the Anasazi.Reviewing tree ring records, including moisture levels, Van West disputed the GreatDrought theory by presenting evidence that enough corn could have been grownduring the drought to support the population, that the Anasazi had weathered manysevere droughts in the past, and that the evacuation actually began before the dryspell set in.
        Belying the popular image of the Anasazi as a peaceable kingdom of farmers andpotters, some new research puts the blame for the evacuation on a bloody internecinewar.    Nothing that the Anasazi had been suffering from malnutrition shorter lifespans and increased infant mortality, Adler suggests that the Anasazi were not able tomove around freely to farm because their once open range was becoming balkanizedinto hostile fiefdoms.     Perhaps as a reaction to drier weather, people in the MesaVerde area began building dams and canals to trap and divert water, and the resultmay have been conflict and warfare.    Unfortunately, other archeologists, havingtrouble envisioning how even drought, balkanization and warfare could make anentire civilization evacuate, are trying to combine archeological evidence withanthropological studies of the modern pueblo Indians to make the case that theAnasazi were roiled by a religious crisis as divisive as European medieval heresies.Analyzing the spread of religious symbols found on rocks or pottery and thedistribution of ceremonial structures, some argue that the Anasazi may have beenpulled from their homeland by a new religion emerging to the south, whoseegalitarian spirit entering a dark age.Ware comes closest to a plausible synthesis ofhis predecessors' theories in suggesting that the Anasazi world was rocked by aspiritual crisis catastrophic enough to cause a collapse of a civilization, and that theuprooted Anasazi apparently embraced a variety of new beliefs on migration to theirnew homes.        Ware further argues that the precipitating factor in the evacuation may have been achange in climate after all. Recent climatological studies suggest that indeed,rainfall patterns were disrupted in a way that might have made the Anasazidisillusioned with their old religion: the customary pattern of heavy snows in thewinter followed by summer monsoons had become unpredictable. Even if therewas not a great drought, moisture may have been coming at the wrong times, and thesummer rains, essential for nourishing the spring crops, were no longer reliable--therain dances were not working anymore. Thus, Ware's theory accommodates thegreatest variety of factors that may explain the Anasazi's evacuation.
【題組】20. Which of the following statements best describes the organization of the firstparagraph?
(A) A historical theory is sketched and a problem with the theory is cited.
(B) A paradox about the origins of a historical phenomenon is pointed out and theauthor's explanation of the paradox is expounded.
(C) A statement about a historical phenomenon is offered and a possiblemisinterpretation of that statement is addressed.
(D) A new explanation for a historical phenomenon is given and evidence for thatexplanation is provided.