托福阅读TPO-24阅读(打印版)

Lake Water （TPO24）

Paragraph 1 Where does the water in a lake come from, and how does water leave it? Water enters a lake from inflowing rivers, from underwater seeps and springs, from overland flow off the surrounding land, and from rain falling directly on the lake surface. Water leaves a lake via outflowing rivers, by soaking into the bed of the lake, and by evaporation. So much is obvious.

Paragraph 2 The questions become more complicated when actual volumes of water are considered: how much water enters and leaves by each route? Discovering the inputs and outputs of rivers is a matter of measuring the discharges of every inflowing and outflowing stream and river. Then exchanges with the atmosphere are calculated by finding the difference between the gains from rain, as measured (rather roughly) by ram gauges, and the losses by evaporation measured with models that correct for the other sources of water loss. For the majority of lakes certainly those surrounded by forests, input from overland flow is too small to have a noticeable effect. Changes in lake level not explained by river flows plus exchanges with the atmosphere must be due to the net difference between what seeps into the lake from the groundwater and what leaks into the groundwater. Note the word "net": measuring the actual amounts of groundwater seepage into the lake and out of the lake is a much more complicated matter than merely inferring their difference.

Paragraph 3 Once all this information has been gathered, it becomes possible to judge whether a lake's flow is mainly due to its surface inputs and outputs or to its underground inputs and outputs. ■If the former are greater, the lake is a surface-water-dominated lake; if the latter, it is a seepage-dominated lake. ■Occasionally, common sense tells you which of these two possibilities applies. ■For example, a pond in hilly country that maintains a steady water level all through a dry summer in spite of having no streams flowing into it must obviously be seepage dominated. Conversely, a pond with a stream flowing in one end and out the other, which dries up when the stream dries up, is clearly surface water dominated. ■

Paragraph 4 By whatever means, a lake is constantly gaining water and losing water: its water does not just sit there, or, anyway, not for long. This raises the matter of a lake's residence time. The residence time is the average length of time that any particular molecule of water remains in the lake, and it is calculated by piding the volume of water in the lake by the rate at which water leaves the lake. The residence time is an average; the time spent in the lake by a given molecule (if we could follow its fate) would depend on the route it took: it might flow through as part of the fastest, most direct current, or it might circle in a backwater for an indefinitely long time

Paragraph 5 Residence times vary enormously. They range from a few days for small lal.es up to several hundred years for large ones: Lake Tahoe, in California, has a residence time of 700 years. The residence times for the Great Lal.es of North America, namely, Lal.es Superior, Michigan. Huron, Erie, and Ontario, are, respectively, 190,100,22,2.5, and 6 years. Lake Erie's is the lowest: although its area is larger than Lake Ontario's, its volume is less than one-third as great because it is so shallow-less than 20 meters on average.

Paragraph 6 A given lake's residence time is by no means a fixed quantity. It depends on the rate at which water enters the lake, and that depends on the rainfall and the evaporation rate. Climatic change (the result of global warming?) is dramatically affecting the residence times of some lakes in northwestern Ontario. Canada. In the period 1970 to 1986, rainfall in the area decreased from 1,000 millimeters to 650 millimeters per annum, while above-average temperatures speeded up the evapotranspiration rate (the rate at which water is lost to the atmosphere through evaporation and the processes of plant life). The result has been that the residence time of one of the la4.es increased from 5 to 18 years during the study period. The slowing down of water renewal leads to a chain of further consequences: it causes dissolved chemicals to become increasingly concentrated, and this, in turn, has a marled effect on all living things in the lake.

Questions

Paragraph 1 Where does the water in a lake come from, and how does water leave it? Water enters a lake from inflowing rivers, from underwater seeps and springs, from overland flow off the surrounding land, and from rain falling directly on the lake surface. Water leaves a lake via outflowing rivers, by soaking into the bed of the lake, and by evaporation. So much is obvious.

1. The phrase “So much” in the passage refers to

?the negative effects of overland flow, ram, and evaporation on river water levels

?water that a lake loses to outflowing rivers.to the lake bed, and to evaporation

?the importance of rivers to the maintenance of lake water levels

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?the information given about ways that water can enter or exit a lake

Paragraph 2 The questions become more complicated when actual volumes of water are considered: how much water

enters and leaves by each route? Discovering the inputs and outputs of rivers is a matter of measuring the discharges of every inflowing and outflowing stream and river. Then exchanges with the atmosphere are calculated by finding

the difference between the gains from rain, as measured (rather roughly) by ram gauges, and the losses by evaporation measured with models that correct for the other sources of water loss. For the majority of lakes certainly those surrounded by forests, input from overland flow is too small to have a noticeable effect. Changes in lake level not explained by river flows plus exchanges with the atmosphere must be due to the net difference between what seeps into the lake from the groundwater and what leaks into the groundwater. Note the word "net": measuring the actual amounts of groundwater seepage into the lake and out of the lake is a much more complicated matter than merely inferring their difference.

2. The word "gains" in the passage is closest in meaning to

?results

?increases

?resources

?savings

3. Which of the following can be inferred from paragraph 2 about the movement of water into a lake?

?Heavy rain accounts for most of the water that enters into lakes

?Rainfall replaces approximately the amount of water lost through evaporation

?Overland flow into lal.es is reduced by the presence of forests

?Seepage has a smaller effect on water level than any other input

4. Why does the author use the phrase “Note the word “net”” in the passage?

?To emphasize the impact of seepage on water levels

?To point out that seepage is calculated differently from river flows and atmospheric exchanges

?To compare the different methods of calculating seepage

?To emphasize the difficulty of obtaining specific values for seepage inputs and outputs

Paragraph 3 Once all this information has been gathered, it becomes possible to judge whether a lake's flow is mainly due to its surface inputs and outputs or to its underground inputs and outputs. If the former are greater, the lake is a surface-water-dominated lake; if the latter, it is a seepage-dominated lake. Occasionally, common sense tells you which of these two possibilities applies. For example, a pond in hilly country that maintains a steady water level all through a dry summer in spite of having no streams flowing into it must obviously be seepage dominated Conversely, a pond with a stream flowing in one end and out the other, which dries up when the stream dries up, is clearly surface water dominated.

5. The word "Conversely" in the passage is closest in meaning to

on the other hand

in the same way

in other words

on average

6. According to paragraph 3, which of the following best describes a seepage-dominated lake?

? A lake that is fed by streams but still has fluctuating water levels

? A lake with a constant water level that has no streams or rivers as inputs

? A lake with a stream flowing into it and a stream flowing out of it

? A lake that has surface and underground inputs but loses water during dry seasons

Paragraph 4 By whatever means, a lake is constantly gaining water and losing water: its water does not just sit there, or, anyway, not for long. This raises the matter of a lake's residence time. The residence time is the average length of time that any particular molecule of water remains in the lake, and it is calculated by piding the volume of water in the lake by the rate at which water leaves the lake. The residence time is an average; the time spent in the lake by a given molecule (if we could follow its fate) would depend on the route it took: it might flow through as part of the fastest, most direct current, or it might circle in a backwater for an indefinitely long time

7. It can be inferred from paragraph 4 that the length of time a given molecule of water remains in a lake

?depends entirely upon the average speed of a lake's currents

?can be measured by the volume of the lake alone

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?can be greater or lesser than the residence time

?is similar to the length of time all other molecules remain in that lake

Paragraph 5 Residence times vary enormously. They range from a few days for small lal.es up to several hundred years for large ones: Lake Tahoe, in California, has a residence time of 700 years. The residence times for the Great Lal.es of North America, namely, Lal.es Superior, Michigan. Huron, Erie, and Ontario, are, respectiv ely, 190,100,22,2.5, and 6 years. Lake Erie's is the lowest: although its area is larger than Lake Ontario's, its volume is less than one-third as great because it is so shallow-less than 20 meters on average.

8. According to paragraph 5, Lake Erie's residence time is lower than Lake Ontario's for which of the following reasons?

?Lake Erie has a larger area than Lake Ontario.

?Lake Ontario is shallower than Lake Erie.

?Lake Ontario has a greater volume than Lake Erie.

?Lake Erie receives less rainfall than Lake Ontario.

9. Why does the author discuss the Great Lakes in paragraph 5?

?To demonstrate the extent to which residence times vary from lake to lake

?To illustrate how residence times are calculated for specific lakes

?To argue that the residence time of a lake increases with area

?To emphasize that Lake Tahoe's residence time is unusually long

Paragraph 6 A given lake's residence time is by no means a fixed quantity. It depends on the rate at which water enters the lake, and that depends on the rainfall and the evaporation rate. Climatic change (the result of global warming?) is dramatically affecting the residence times of some lakes in northwestern Ontario. Canada. In the period 1970 to 1986, rainfall in the area decreased from 1,000 millimeters to 650 millimeters per annum, while above-average temperatures speeded up the evapotranspiration rate (the rate at which water is lost to the atmosphere through evaporation and the processes of plant life). The result has been that the residence time of one of the l a4.es increased from 5 to 18 years during the study period. The slowing down of water renewal leads to a chain of further consequences: it causes dissolved chemicals to become increasingly concentrated, and this, in turn, has a marled effect on all living things in the lake.

10. The word “further" in the passage is closest in meaning to

?expected

?additional

?serious

?unfortunate

11. According to paragraph 6; which of the following explains the increase in residence time of some lakes of northwestern Ontario?

?The amount of water flowing into the lakes has increased.

?The rate of evaporation has decreased more sharply than the amount of rainfall.

?The renewal of the lakes' water has slowed due to changes in climate.

?Plants have required less water from the lakes

11. According to paragraph 6; which of the following explains the increase in residence time of some lakes of northwestern Ontario?

?The amount of water flowing into the lakes has increased.

?The rate of evaporation has decreased more sharply than the amount of rainfall.

?The renewal of the lakes' water has slowed due to changes in climate.

?Plants have required less water from the lakes

Paragraph 3 Once all this information has been gathered, it becomes possible to judge whether a lake's flow is mainly due to its surface inputs and outputs or to its underground inputs and outputs. ■If the former are greater, the lake is a surface-water-dominated lake; if the latter, it is a seepage-dominated lake. ■Occasionally, common sense tells you which of these two possibilities applies. ■For example, a pond in hilly country that maintains a steady water level all through a dry summer in spite of having no streams flowing into it must obviously be seepage dominated Conversely, a pond with a stream flowing in one end and out the other, which dries up when the stream dries up, is clearly surface water dominated. ■

13．Look at the four squares [■] that indicate where the following sentence could be added to the passage. Of

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course, a lake may be neither surface-water- nor seepage-dominated if, for example, its inputs are predominantly surface and its outputs are predominantly seepage.Where would the sentence best fit? Click on a square to add the sentence to the passage.

14．Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THERR answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.Water enters, remains, and eventually leaves a lake in a variety of ways. Click on 3 Answers.

?By measuring the water quantities at each of a lake's inputs and outputs, it can be determined whether water enter the lake mainly from surface or groundwater sources

?It is sometimes possible to decide whether a lake is surface water dominated or seepage dominated by simple observation at different seasons.

?The residence times of surface-water-dominated lakes are usually longer than those of seepage-dominated lakes

?Changes in lake level and volume are caused principally by the amount of evaporation of water into the atmosphere

?The average period of time that molecules of water spend in a lake-the residence time-varies from lake to lake and over time within a particular lake.

?The residence time of a lake frequently depends on the kinds of organisms to be found in the lake

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Breathing During Sleep

Paragraph1 Of all the physiological differences in human sleep compared with wakefulness that have been discovered in the last decade, changes in respiratory control are most dramatic. Not only are there differences in the level of the functioning of respiratory systems, there are even changes in how they function. Movements of the rib cage for breathing are reduced during sleep, making the contractions of the diaphragm more important. ■Yet because of the physics of lying down, the stomach applies weight against the diaphragm and makes it more difficult for t he diaphragm to do its job. ■However, there are many other changes that affect respiration when asleep.

Paragraph2 ■During wakefulness, breathing is controlled by two interacting systems. ■The first is an automatic, metabolic system whose control is centered in the brain stem. It subconsciously adjusts breathing rate and dep th in order to regulate the levels of carbon dioxide (C02,) and oxygen (02,), and the acid-base ratio in the blood. The second system is the voluntary, behavioral system. Its control center is based in the forebrain, and it regulates breathing for use in speech, singing, sighing, and so on. It is capable of ignoring or overriding the automatic, metabolic system and produces an irregular pattern of breathing.

Paragraph3 During NREM (the phase of sleep in which there is no rapid eye movement) breathing becomes deeper and more regular, but there is also a decrease in the breathing rate, resulting in less air being exchanged overall. This occurs because during NREM sleep the automatic, metabolic system has exclusive control over breathing and the body uses less oxygen and produces less carbon dioxide. Also, during sleep the automatic metabolic system is less responsive to carbon dioxide levels and oxygen levels in the blood. Two things result from these changes in breathing control that occurs during sleep. First, there may be a brief cessation or reduction of breathing when falling asleep as the sleeper waxes and wanes between sleep and wakefulness and their differing control mechanisms. Second, once sleep is fully obtained, there is an increase of carbon dioxide and a decrease of oxygen in the blood that persists during NREM.

Paragraph4 But that is not all that changes. During all phases of sleep, several changes in the air passages have been observed. It tales twice as much effort to breathe during sleep because of greater resistance to airflow in the airways and changes in the efficiency of the muscles used for breathing. Some of the muscles that help keep the upper airway open when breathing tend to become more relaxed during sleep, especially during REM (the phase of sleep in which there is rapid eye movement). Without this muscular action, inhaling is like sucking air out of a balloon-the narrow passages tend to collapse. Also there is a regular cycle of change in resistance between the two sides of the nose. If something blocks the "good" side, such as congestion from allergies or a cold, then resistance increases dramatically. Coupled with these factors is the loss of the complex interactions among the muscles that can change the route of airflow from nose to mouth.

Paragraph5 Other respiratory regulating mechanisms apparently cease functioning during sleep. For example, during wakefulness there is an immediate. Automatic, adaptive increase in breathing effort when inhaling is made more difficult (such as breathing through a restrictive face mask). This reflexive adjustment is totally absent during NREM sleep. Only after several inadequate breaths under such conditions, resulting in the considerable elevation of carbon dioxide and reduction of oxygen in the blood, is breathing effort adjusted. Finally, the coughing reflex in reaction to irritants in the airway produces not a cough during sleep but a cessation of breathing. If the irritation is severe enough, a sleeping person will arouse, clear the airway, then resume breathing and likely return to sleep.

Paragraph6 Additional breathing changes occur during REM sleep that are even more dramatic than the changes that occur during NREM. The amount of air exchanged is even lower in REM than NREM because, although breathing is more rapid in REM, it is also more irregular, with brief episodes of shallow breathing or absence of breathing. In addition, breathing during REM depends much more on the action of the diaphragm and much less on rib cage action.

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Questions

Paragraph1 Of all the physiological differences in human sleep compared with wakefulness that have been discovered in the last decade, changes in respiratory control are most dramatic. Not only are there differences in the level of the functioning of respiratory systems, there are even changes in how they function. Movements of the rib cage for breathing are reduced during sleep, making the contractions of the diaphragm more important. Yet because of the physics of lying down, the stomach applies weight against the diaphragm and makes it more difficult for the diaphragm to do its job. However, there are many other changes that affect respiration when asleep.

1. According to paragraph 1 .which of the following can be inferred about the diaphragm during sleep?

?During sleep the diaphragm requires increased movement of the rib cage.

?The diaphragm helps with breathing as movements of the rib cage decrease during sleep.

?The diaphragm requires a great amount of pressure to function properly.

?The diaphragm contributes to the effective functioning of the rib cage

Paragraph2 During wakefulness, breathing is controlled by two interacting systems. The first is an automatic, metabolic system whose control is centered in the brain stem. It subconsciously adjusts breathing rate and depth in order to regulate the levels of carbon dioxide (C02,) and oxygen (02,), and the acid-base ratio in the blood. The second system is the voluntary, behavioral system. Its control center is based in the forebrain, and it regulates bre athing for use in speech, singing, sighing, and so on. It is capable of ignoring or overriding the automatic, metabolic system and produces an irregular pattern of breathing.

2. According to paragraph 2, all of the following are true of the voluntary breathing system EXCEPT:

?It has its control center in the brain stem

?It controls breathing for a number of activities during wakefulness.

?It is able to bypass the automatic system.

?It produces an irregular breathing pattern

Paragraph3 During NREM (the phase of sleep in which there is no rapid eye movement) breathing becomes deeper and more regular, but there is also a decrease in the breathing rate, resulting in less air being exchanged overall. This occurs because during NREM sleep the automatic, metabolic sy stem has exclusive control over breathing and the body uses less oxygen and produces less carbon dioxide. Also, during sleep the automatic metabolic system is less responsive to carbon dioxide levels and oxygen levels in the blood. Two things result from these changes in breathing control that occurs during sleep. First, there may be a brief cessation or reduction of breathing when falling asleep as the sleeper waxes and wanes between sleep and wakefulness and their differing control mechanisms. Second, onc e sleep is fully obtained, there is an increase of carbon dioxide and a decrease of oxygen in the blood that persists during NREM.

3. The word "exclusive" in the passage is closest in meaning to

?consistent

?perfect

?partial

?sole

4. According to paragraph 3, which of the following may occur just before NREM sleep begins?

?The automatic, metabolic system may increase its dependence on air exchanges.

?Breathing can stop for a short time as a person falls asleep.

?An increase in the oxygen level in the blood can occur as sleep becomes fully obtained

?The level of carbon dioxide in the blood may drop suddenly

Paragraph4 But that is not all that changes. During all phases of sleep, several changes in the air passages have been observed. It tales twice as much effort to breathe during sleep because of greater resistance to airflow in the airways and changes in the efficiency of the muscles used for breathing. Some of the muscles that help keep the upper airway open when breathing tend to become more relaxed during sleep, especially during REM (the phase of sleep in which there is rapid eye movement). Without this muscular action, inhaling is like sucking air out of a balloon-the narrow passages tend to collapse. Also there is a regular cycle of change in resistance between the two sides of the nose. If something blocks the "good" side, such as congestion from allergies or a cold, then resistance increases dramatically. Coupled with these factors is the loss of the complex interactions among the muscles that can change the route of airflow from nose to mouth.

5. What is the author's purpose in stating that 0Inhaling is like sucking air out of a balloon"?

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?To refute the argument that additional effort is necessary for breathing during sleep

?To argue that REM sleep is more important than NREM sleep

?To illustrate the difficulty of breathing during sleep

?To illustrate how blockage of narrow passages can be prevented during sleep

6. All of the following are mentioned in paragraph 4 as being characteristic of breathing during sleep EXCEPT

?relaxation of the muscles involved in the respiratory system

?changes in resistance between the two sides of the nose

?easier airflow in the passages of the upper airway

?absence of certain complex muscle interactions

Paragraph5 Other respiratory regulating mechanisms apparently cease functioning during sleep. For example, during wakefulness there is an immediate. Automatic, adaptive increase in breathing effort when inhaling is made

more difficult (such as breathing through a restrictive face mask). This reflexive adjustment is totally absent during NREM sleep. Only after several inadequate breaths under such conditions, resulting in the considerable elevation of

carbon dioxide and reduction of oxygen in the blood, is breathing effort adjusted. Finally, the coughing reflex in reaction to irritants in the airway produces not a cough during sleep but a cessation of breathing. If the irritation is severe enough, a sleeping person will arouse, clear the airway, then resume breathing and likely return to sleep.

7. According to paragraph 5; what happens during NREM sleep when inhaling is difficult?

?There is an immediate, automatic, adaptive increase in breathing effort

?The sleeping person tales several inadequate breaths before the breathing effort is adjusted

?The coughing reflex causes the breathing effort to adjust.

?The airways become cleared as the blood removes irritants.

8. It can be inferred from paragraph 5 that a very mild irritation during sleep will likely cause

?the sleeping person to increase the breathing effort

?wake up and remove the source of irritation

?cough while still sleeping

?stop breathing temporarily while still sleeping

9. The word "considerable" in the passage is closest in meaning

?significant

?steady

?usual

?necessary

10. The word "resume" in the passage is closest in meaning to

?reduce

?stop

?readjust

?restart

11. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.

?Because breathing is more shallow and irregular in REM than in NREM, less air is exchanged in REM

?Breathing in NREM is less effective than breathing in REM because of irregular episodes of rapid breathing during NREM.

?Because breathing is more rapid in NREM sleep than in REM sleep, breathing often becomes shallow.

?Although REM has brief episodes of shallow breathing or lack of breathing, breathing is more rapid than in NRFM Paragraph1 Of all the physiological differences in human sleep compared with wakefulness that have been discovered in the last decade, changes in respiratory control are most dramatic. Not only are there differences in the level of the functioning of respiratory systems, there are even changes in how they function. Movements of the rib cage for breathing are reduced during sleep, making the contractions of the diaphragm more important. ■Yet because of the physics of lying down, the stomach applies weight against the diaphragm and makes it more difficult for the diaphragm to do its job. ■However, there are many other changes that affect respiration when asleep.

Paragraph2 ■During wakefulness, breathing is controlled by two interacting systems. ■The first is an automatic,

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metabolic system whose control is centered in the brain stem. It subconsciously adjusts breathing rate and depth in order to regulate the levels of carbon dioxide (C02,) and oxygen (02,), and the acid-base ratio in the blood. The second system is the voluntary, behavioral system. Its control center is based in the forebrain, and it regulates breathing for use in speech, singing, sighing, and so on. It is capable of ignoring or overriding the automatic, metabolic system and produces an irregular pattern of breathing.

12. Look at the four squares [■] that indicate where the following sentence could be added to the passage. To better understand breathing during sleep, it is, however, helpful to first understand how respiration works in general. Where would the sentence best fit? Click on a square to add the sentence to the passage.

13 Directions: From the seven statements below, select the statements that correctly characterise breathing during wakefulness and those statements that correctly characterise breathing during sleep. Two of the answer choices will NOT be used. This question is worth 3 points.

Sleep (3 answers)

Wakefulness (2 answers)

?The role of the rib cage increases and the role of the diaphragm decreases

?Carbon dioxide in blood rises and oxygen drops

?The coughing reflex is extremely complex

? A great deal of effort is used for breathing

?Upper airways are resistant to colds and allergies

?There is a drop in the volume of air that is exchanged

?Automatic and voluntary respiratory systems are both involved

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Moving into Pueblos

Paragraph1 In the Mesa Verde area of the ancient North American Southwest, living patterns changed in the

thirteenth century, with large numbers of people moving into large communal dwellings 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 probably traumatic. Few of the cultural traditions and rules that today allow us to deal with dense populations existed for these people accustomed to household autonomy and the ability to move around the landscape almost at will. ■And besides the awkwardness of having to share walls with neighbors, living in aggregated pueblos introduced other problems. ■For people in cliff dwellings, hauling water, wood, and food to their homes was a major chore. ■The stress on local resources, especially in the firewood needed for daily cooling and warmth, was particularly intense, and conditions in aggregated pueblos were not very hygienic.■

Paragraph2 Given all the disadvantages of living in aggregated town, why did people in the thirteenth century move into these closely packed quarters? For transitions of such suddenness archaeologists consider either pull factors (benefits that drew families together) or push factors (some external threat or crisis that forced people to aggregate). In this case, push explanations dominate.

Paragraph3 Population growth is considered a particularly influential push. After several generations of population growth, people packed the landscape in densities so high that communal pueblos may have been a necessary outcome. Around Sand Canyon, for example, populations grew from 5-12 people per square kilometer in the tenth century to as many as 30-50 by the 1200s. As densities increased, domestic architecture became larger, culminating in crowded

pueblos. Some scholars expand on this idea by emphasizing a corresponding need for arable land to feed growing numbers of people: construction of small dams, reservoirs, terraces, and field houses indicates that farmers were intensifying their efforts during the 1200s. Competition for good farmland may also have prompted people to bond together to assert rights over the best fields.

Paragraph4 Another important push was the onset of the Little Ice Age, a climatic phenomenon that led to cooler temperatures in the Northern Hemisphere. Although the height of the Little Ice Age was still around the corner, some evidence suggests that temperatures were falling during the thirteenth century. The environmental changes associated with this transition are 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 growing season. As the Little Ice Age progressed, farmers probably moved their fields to lower elevations，infringing on the lands of other farmers and pushing people together, thus contributing to the aggregations. Archaeologists identify a corresponding shift in populations toward the south and west toward Mesa Verde and away from higher elevations. Paragraph5 In the face of all these pushes, people in the Mesa Verde area had yet another reason to move into communal villages: the need for greater cooperation. Sharing and cooperation were almost certainly part of early Puebloan life, even for people living in largely independent single-household residences scattered across the landscape. Archaeologists find that even the most isolated residences during the eleventh and twelfth centuries obtained some pottery and probably food, from some distance away, while major ceremonial events were opportunities for sharing food and crafts. Scholars believe that this cooperation allowed people to contend with a patchy environment in which precipitation and other resources varied across the landscape: if you produce a lot of food one year, you might trade it for pottery made by a distant ally who is having difficulty with crops-and the next year, the flow of goods might go in the opposite direction. But all of this appears to have changed in the thirteenth century. Although the climate remained as unpredictable as ever between one year and the next, it became much less locally perse. In a bad year for farming, everyone was equally affected. No longer was it helpful to share widely. Instead, the most sensible thing would be for neighbors to combine efforts to produce as much food as possible, and thus aggregated towns were a sensible arrangement.

Questions

Paragraph1 In the Mesa Verde area of the ancient North American Southwest, living patterns changed in the thirteenth century, with large numbers of people moving into large communal dwellings 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 probably traumatic. Few of the cultural traditions and rules that today allow us to deal with dense populations existed for these people accustomed to household autonomy and the ability to move around the landscape almost at will. And besides the awkwardness of having to share walls with neighbors, living in aggregated pueblos introduced other problems. For people in cliff dwellings, hauling water, wood, and food to their homes was a major chore. The stress on local reso urces, especially in the firewood needed for daily cooling and warmth, was particularly intense, and conditions in aggregated pueblos were

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not very hygienic.

1. The word "traumatic" in the passage is closest in meaning to

?essential

?highly stressful

?highly unusual

?unwise

2. The word "intense" in the passage is closest in meaning to

?strong

?questionable

?obvious

?deliberate

3. According to paragraph 1, before the thirteenth century the people of southwestern North America lived in households that

?shared daily chores with neighboring households

?occupied dwellings that were built into the sides of cliffs

?were largely free to conduct their lives as they pleased

?enforced common standards of behavior and cooperative conduct within their communities

4. Which of the following best indicates the organization of paragraph 1?

?It presents the conditions that caused a change in a population's living patterns and then explains why those conditions got worse

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

?It casts doubt on one explanation of the move to pueblos and then introduces an alternative explanation that the passage will defend

?It describes a major change in a population's living patterns and then presents a number of problems that resulted from that change.

Paragraph3 Population growth is considered a particularly influential push. After several generations of population growth, people packed the landscape in densities so high that communal pueblos may have been a necessary outcome. Around Sand Canyon, for example, populations grew from 5-12 people per square kilometer in the tenth century to as many as 30-50 by the 1200s. As densities increased, domestic architecture became larger, culminating in crowded pueblos. Some scholars expand on this idea by emphasizing a corresponding need for arable land to feed growing numbers of people: construction of small dams, reservoirs, terraces, and field houses indicates that farmers were intensifying their efforts during the 1200s. Competition for good farmland may also have prompted people to bond together to assert rights over the best fields.

5. According to paragraph 3, which of the following was one of the consequences of increasing population densities?

?People were increasingly crowded into collections of large housing units

?People stopped planting crops that have relatively low yields.

?Domestic buildings were pushed beyond the canyon limits.

?The natural landscape was destroyed.

6. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information

?Some scholars expand on this idea by emphasizing a corresponding need for arable land to feed growing numbers of people: construction of small dams, reservoirs, terraces, and field houses indicates that farmers were intensifying their efforts during the 1200s.

?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 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.

?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

?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.

Paragraph4 Another important push was the onset of the Little Ice Age, a climatic phenomenon that led to cooler

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temperatures in the Northern Hemisphere. Although the height of the Little Ice Age was still around the corner, some evidence suggests that temperatures were falling during the thirteenth century. The environmental changes associated with this transition are 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 growing season. As the Little Ice Age progressed, farmers probably moved their fields to lower elevations，infringing on the lands of other farmers and pushing people together, thus contributing to the aggregations. Archaeologists identify a corresponding shift in populations toward the south and west toward Mesa Verde and away from higher elevations. 7. The word "transition" in the passage is closest in meaning to

?change

?climate

?decline

?problem

8. Why does the author state that " Growing food at these elevations is always difficult because of the short growing season "?

?To explain why the higher elevations were always relatively sparsely populated

?To suggest that any worsening of conditions would have significant consequences

?To emphasise how resourceful the people growing food at these elevations were

?To argue that farming was not the primary source of food at high elevations

9. According to paragraph 4, what did farmers do in response to falling temperatures during the Little Ice Age?

?Moved to areas away from Mesa Verde

?Moved closer to the northeastern part of Mesa Verde

?Began to cultivate crops adapted to a short growing season

?Gave up the cultivation of the highest-lying lands

Paragraph5 In the face of all these pushes, people in the Mesa Verde area had yet another reason to move into communal villages: the need for greater cooperation. Sharing and cooperation were almost certainly part of early Puebloan life, even for people living in largely independent single-household residences scattered across the landscape. Archaeologists find that even the most isolated residences during the eleventh and twelfth centuries obtained some pottery and probably food, from some distance away, while major ceremonial events were opportunities for sharing food and crafts. Scholars believe that this cooperation allowed people to contend with a patchy environment in which precipitation and other resources varied across the landscape: if you produce a lot of food one year, you might trade it for pottery made by a distant ally who is having difficulty with crops-and the next year, the flow of goods might go in the opposite direction. But all of this appears to have changed in the thirteenth century. Although the climate remained as unpredictable as ever between one year and the next, it became much less locally perse. In a bad year for farming, everyone was equally affected. No longer was it helpful to share widely. Instead, the most sensible thing would be for neighbors to combine efforts to produce as much food as possible, and thus aggregated towns were a sensible arrangement

10. According to paragraph 5, major ceremonial events were occasions for

?leaders to persuade people from the countryside to move into a pueblo

?farmers to collect information about where crops could br reliably grown

?people to develop better techniques for producing pottery and crafts

?people in the early Puebloan era to share farm and craft products

11. According to paragraph 5, which of the following was a reason people in the Mesa Verde area formed communal villages in the thirteenth century?

?The climate in the Mesa Verde area became more locally perse.

?Inpiduals were no longer interested in exchanging pottery and food.

?Cooperation between people became more important for survival.

?Bad years of farming began to occur more frequently.

12. Paragraph 5 supports which of the following statements about cooperation among the people in the Mesa Verde area from the eleventh through the thirteenth century?

?Cooperation allowed many households to give up farming and to specialize in making pottery and crafts.

?People went from exchanging food and crafts they inpidually produced to sharing in a cooperative effort to produce as much food as possible.

?Overtime there was less cooperation as farmers competed with each other for trade with distant areas.

?Inpiduals stopped cooperating with each other because they did not have enough food for themselves.

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Paragraph1 In the Mesa Verde area of the ancient North American Southwest, living patterns changed in the thirteenth century, with large numbers of people moving into large communal dwellings 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 probably traumatic. Few of the cultural

traditions and rules that today allow us to deal with dense populations existed for these people accustomed to household autonomy and the ability to move around the landscape almost at will. ■And besides the awkwardness of having to share walls with neighbors, living in aggregated pueblos introduced other problems. ■For people in cliff dwellings, hauling water, wood, and food to their homes was a major chore. ■The stress on local resources, especially in the firewood needed for daily cooling and warmth, was particularly intense, and conditions in aggregated pueblos were not very hygienic.■

13．Look at the four squares [■] that indicate where the following sentence could be added to the passage.

Performing everyday household tasks required more effort Where would the sentence best fit? Click on a square to add the sentence to the passage.

14．Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THERR answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points. In the thirteenth century, the people in the Mesa Verde area went from living in scattered independent households to living in large pueblos.

?Because the thirteenth-century inhabitants of the Mesa Verde area did not have the cultural expectations of today's city dwellers, they easily adapted to communal life

?From the eleventh century onward, farmers began to increase food production on existing farmland and started bringing more land under cultivation

?The primary reason for moving to pueblos was the social benefits associated with communal life.

?Even though living in pueblos had disadvantages, the population of the area had grown so large that there may have been no other arrangement that would have met its needs

? A development that contributed to increasing population densities was a cooling climate that led many people to leave the coldest areas and crowd into climatically more favorable areas

?People were brought together by the need to produce food cooperatively, as the use of food surpluses in one place to relieve shortages in another ended due to a change in climate

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