In the Mesa Verde area of theancientNorth American Southwest, living patterns changed in the thirteenthcentury, with large numbers of people moving into largecommunaldwellings called pueblos, often constructed at the edges of canyons, especially on the sides of cliffs. Abandoning small extended-family households to move into these large pueblos with dozens if not hundreds of other people was probablytraumatic. Few of the cultural traditions and rules that today allow us todealwithdensepopulations existed for these peopleaccustomedtohouseholdautonomyand theabilityto move around thelandscapealmost at will. Andbesidesthe awkwardness of having to share walls with neighbors, living in aggregated pueblos introduced other problems. For people incliffdwellings, hauling water, wood, and food to their homes was amajorchore. Thestressonlocalresources, especially in the firewood needed for daily cooking and warmth, was particularlyintense, and conditions in aggregated pueblos were not very hygienic.

Givenall the disadvantages of living in aggregated towns, why did people in the thirteenthcenturymove into these closelypackedquarters? For transitions of such suddenness, archaeologistsconsidereither pull factors (benefits that drew families together) or push factors (someexternalthreat or crisis that forced people toaggregate). In this case, push explanationsdominate.

Populationgrowth is considered a particularlyinfluentialpush. After several generations ofpopulationgrowth, peoplepackedthelandscapein densities so high thatcommunalpueblos may have been a necessaryoutcome. Around SandCanyon, for example, populations grew from 5 -12 people persquarekilometer in the tenthcenturyto as many as 30 - 50 by the 1200s. As densities increased,domesticarchitecturebecame larger, culminating in crowded pueblos. Some scholarsexpandon this idea by emphasizing a corresponding need forarableland to feed growing numbers of people:constructionof small dams, reservoirs, terraces, andfieldhouses indicates that farmers were intensifying their efforts during the 1200s. Competition for good farmland may also have prompted people tobondtogether toassertrights over the best fields.

Another important push was the onset of the Little Ice Age, aclimaticphenomenonthat led to cooler temperatures in the Northern Hemisphere. Although the height of the Little Ice Age was still around the corner, someevidencesuggests that temperatures were falling during the thirteenthcentury. Theenvironmentalchanges associated with thistransitionare not fully understood, but people living closest to the San Juan Mountains, to the northeast of Mesa Verde, were affected first. Growing food at these elevations is always difficult because of the short growingseason. As the Little Ice Age progressed, farmers probably moved their fields tolowerelevations, infringing on the lands of other farmers and pushing people together, thus contributing to the aggregations. Archaeologistsidentifya correspondingshiftin populations toward the south and west toward Mesa Verde and away from higher elevations.

In the face of all these pushes, people in the Mesa Verde area had yet anotherreasonto move intocommunalvillages: the need for greatercooperation. Sharing andcooperationwere almost certainly part of early Puebloan life, even for people living in largelyindependentsingle-household residencesscatteredacrossthelandscape. Archaeologists find that even the mostisolatedresidences during the eleventh and twelfth centuries obtained somepottery, and probably food, from some distance away, whilemajorceremonialevents were opportunities for sharing food and crafts. Scholars believe that thiscooperationallowed people tocontendwith a patchy environment in whichprecipitationand other resourcesvariedacrossthe landscape: if you produce a lot of food one year, you mighttradeit forpotterymade by adistantallywho is having difficulty with crops—and the next year, the flow of goods might go in theoppositedirection. But all of this appears to have changed thirteenthcentury. Although theclimateremained asunpredictableas ever between one year and the next, it became much lesslocallydiverse. In a bad year for farming, everyone was equally affected. No longer was it helpful to share widely. Instead, the mostsensiblething would be for neighbors tocombineefforts to produce as much food as possible, and thus aggregated towns were asensiblearrangement.

Questions:
question_stem: The word "traumatic" meaning to
choices: tag: A
text: Essential

tag: B
text: highly stressful

tag: C
text: highly unusual

tag: D
text: unwise
answer_key: B
explanation: B  traumatic: 受伤的，不顺心的。A 选项是必要的，B 是非常有压力的，C 是非常不寻常的，D 是不明智的。所以正确答案是 highly stressful。

question_stem: The word "intense" in the passage is closest in meaning to
choices: tag: A
text: strong

tag: B
text: questionable

tag: C
text: obvious

tag: D
text: deliberate
answer_key: A
explanation: A  intense: 强烈的，紧张的。A 是强烈的，B 是可疑的，有问题的，C 是明显的，D 是深思熟虑的。所以正确答案是 strong。

question_stem: According to paragraph 1, before the thirteenth century the people of southwestern North America lived in households that
choices: tag: A
text: shared daily chores with neighboring households

tag: B
text: occupied dwellings that were built into the sides of cliffs

tag: C
text: were largely free to conduct their lives as they pleased

tag: D
text: enforced common standards of behavior and cooperative conduct within their communities
answer_key: C
explanation: C 如果这道题以十三世纪做关键词定位的话，读完第一句也不知道选哪个，因此用排除法较好。A 的 chore 做关键词定位至倒数第二句，但原文只是列举了 chore，没说选项说的 share，A 错；B 的 dwelling 和 sides of the cliffs 做关键词定位至第一句，但建在 cliff 的是 pueblo，不是十三世纪之前，所以 B 错；C 在原文中没有明确说明，但看首句会发现十三世纪变化了，十三世纪以后大家一起住，有很多问题，也就是说十三世纪之前大家都是自己住自己的，也就是 C 说的 conduct their lives as they pleased，C 正确；D 原文完全没说，不选

question_stem: Which of the following best indicates the organization of paragraph 1?
choices: tag: A
text: It presents the conditions that caused a change in a population' s living patterns and then explains why those conditions got worse.

tag: B
text: It identifies certain present-day cultural traditions and rules and then traces them to their roots in the thirteenth century.

tag: C
text: It casts doubt on one explanation of the move to pueblos and then introduces an alternative explanation that the passage will defend.

tag: D
text: It describes a major change in a population' s living patterns and then presents a number of problems that resulted from that change.
answer_key: D
explanation: D 问全段的题，看头尾。第一句说十三世纪人们的生活方式发生了变化，很多人都搬到了 pueblo；而后半段从倒数第三句到最后都在说这种现象产生的一系列问题，所以是先陈述现象，后说这种现象产生的问题，答案是 D。A 的 why those conditions get worse，B 的 present cultural condition 和 C 的 an alternative explanation 原文都没说.

question_stem: According to paragraph 3, which of the following was one of the consequences of increasing population densities?
choices: tag: A
text: People were increasingly crowded into collections of large housing units.

tag: B
text: People stopped planting crops that have relatively low yields.

tag: C
text: Domestic buildings were pushed beyond the canyon limits.

tag: D
text: The natural landscape was destroyed.
answer_key: A
explanation: A 以 density 做关键词定位至第二句，说经过若干代人口增长，density 实在太大，使得 pueblo 成为一个不可避免的结果，所以正确答案是 A，crowd into collections of large housing units。B 的 crop，C 的 canyon limits 和 D 的 destroy 原文都没讲.

question_stem: Which of the sentences below best expresses the essential information in the highlighted sentence in the passage (paragraph 4)?Incorrect choices change the meaning in important ways or leave out essential information.
choices: tag: A
text: Some scholars even claim that the intensification of farmers' various efforts during the 1200s led to further population growth and the consequent need for more arable land.

tag: B
text: Evidence of intensifying agriculture in the 1200s indicates a need to feed a larger population and so extends the argument that a growing population was the cause of the move to pueblos.

tag: C
text: During the 1200s, farmers met the demand for more arable land, but they also succeeded in cultivating existing land more intensively with the help of agricultural construction projects.

tag: D
text: Some scholars feel strongly that the construction of small dams, reservoirs, terraces, and field houses in the thirteenth century is independent evidence for growth in the number of people.
answer_key: B
explanation: B 原文的结构是 scholar 强调需要耕地来保证增长人口的食物，construction indicates blabla。答案是 B，A 的 effort lead to 人口增长纯属胡说；C 的转折完全不对，而且 farmer 满足耕地需要也不对；D 的 independent evidence 不对。

question_stem: The word "transition" in the passage is closest in meaning to
choices: tag: A
text: change

tag: B
text: climate

tag: C
text: decline

tag: D
text: problem
answer_key: A
explanation: A  transition: 过渡，变化。A 是变化，B 是气候，C 是下降，D 是问题。所以答案是 A。

question_stem: Why does the author state that "Growing food at these elevations is always difficult because of the short growing season"?
choices: tag: A
text: To explain why the higher elevations were always relatively sparsely populated

tag: B
text: To suggest that any worsening of conditions would have significant consequences

tag: C
text: To emphasize how resourceful the people growing food at these elevations were

tag: D
text: To argue that farming was not the primary source of food at high elevations
answer_key: B
explanation: B 修辞目的题，修辞点所在的句子仅仅是一个例子，所以往前看，但前一句仍然是例子，所以看首句。首句说 Little Ice Age 对 push 有影响，而选项中说到影响的只有 B 的 consequence，所以正确答案是 B，而且最后一句话说人口迁徙也可以说明 Little Ice Age 的影响。A 的 sparsely populated，C 的 resourceful 和 D 的 primary source of food 原文都没有任何相关信息。