1.Excavation of the ancient city of Kourion on the island of Cyprus revealed a pattern of debris and collapsed buildings typical of towns devastated by earth-quakes. Archaeologists have hypothesized that the destruction was due to a major earthquake known to have occurred near the island in A.D.365.
Which of the following， if true， most strongly supports the archaeologists' hypothesis？
（A） Bronze ceremonial drinking vessels that are often found in graves dating from years preceding and following A.D.365 were also found in several graves near Kourion.
（B） No coins minted after A.D.365 were found in Kourion， but coins minted before that year were found in abundance.
（C） Most modern histories of Cyprus mention that an earthquake occurred near the island in A.D.365.
（D） Several small statues carved in styles current in Cyprus in the century between A.D.300 and 400 were found in Kourion. （E） Stone inscriptions in a form of the Greek alphabet that was definitely used in Cyprus after A.D.365 were found in Kourion.
2.In Swartkans territory， archaeologists discovered charred bone fragments dating back 1 million years. Analysis of the fragments， which came from a variety of animals， showed that they had been heated to temperatures no higher than those produced in experimental campfires made from branches of white stink-wood， the most common tree around Swartkans.
Which of the following， if true， would， together with the information above， provide the best basis for the claim that the charred bone fragments are evidence of the use of fire by early hominids？
（A） The white stinkwood tree is used for building material by the present day inhabitants of Swartkans.
（B） Forest fires can heat wood to a range of temperatures that occur in campfires.
（C） The bone fragments were fitted together by the archaeologists to form the complete skeletons of several animals.
（D） Apart from the Swartkans discovery， there is reliable evidence that early hominids used fire as many as 500 thousand years ago.
（E） The bone fragments were found in several distinct layers of limestone that contained primitive cutting tools known to have been used by early hominids.
3.Black Americans are， on the whole， about twice as likely as White Americans to develop high blood pressure. This likelihood also holds for westernized Black Africans when compared to White Africans. Researchers have hypothesized that this predisposition in westernized Blacks may reflect an interaction between western high-salt diets and genes that adapted to an environmental scarcity of salt.
Which of the following statements about present-day， westernized Black Africans， if true， would most tend to confirm the researchers' hypothesis？
（A） The blood pressures of those descended from peoples situated throughout their history in Senegal and Gambia， where salt was always available， are low.
（B） The unusually high salt consumption in certain areas of Africa represents a serious health problem.
（C） Because of their blood pressure levels， most White Africans have markedly decreased their salt consumption.
（D） Blood pressures are low among the Yoruba， who， throughout their history， have been situated far inland from sources of sea salt and far south of Saharan salt mines.
（E） No significant differences in salt metabolism have been found between those people who have had salt available throughout their history and those who have not.
4.Two decades after the Emerald River Dam was built， none of the eight fish species native to the Emerald River was still reproducing adequately in the river below the dam. Since the dam reduced the annual range of water temperature in the river below the dam from 50 degrees to 6 degrees， scientists have hypothesized that sharply rising water temperatures must be involved in signaling the native species to begin the reproductive cycle.
Which of the following statements， if true， would most strengthen the scientists' hypothesis？
（A） The native fish species were still able to reproduce only in side streams of the river below the dam where the annual temperature range remains approximately 50 degrees.
（B） Before the dam was built， the Emerald River annually overflowed its banks， creating backwaters that were critical breeding areas for the native species of fish.
（C） The lowest recorded temperature of the Emerald River before the dam was built was 34 degrees， whereas the lowest recorded temperature of the river after the dam was built has been 43 degrees.
（D）Nonnative species of fish， introduced into the Emerald River after the dam was built， have begun competing with the declining native fish species for food and space.
（E） Five of the fish species native to the Emerald River are not native to any other river in North America.
5. An advertisement designed to convince readers of the great durability of automobiles manufactured by the Deluxe Motor Car Company cites as evidence the fact that over half of all automobiles built by the company since 1970 are still on the road today， compared to no more than a third for any other manufacturer.
Which of the following， if true， most strongly supports the advertisement's argument？
（A） After taking inflation into account， a new Deluxe automobile costs only slightly more than a new model did in 1970.
（B） The number of automobiles built by Deluxe each year has not increased sharply since 1970.
（C） Owners of Deluxe automobiles typically keep their cars well maintained.
（D） Since 1970， Deluxe has made fewer changes in the automobiles it manufactures than other car companies have made in their automobiles.
（E） Deluxe automobiles have been selling at relatively stable prices in recent years.
6.Six months or so after getting a video recorder， many early buyers apparently lost interest in obtaining videos to watch on it. The trade of businesses selling and renting videos is still buoyant， because the number of homes with video recorders is still growing. But clearly， once the market for video recorders is saturated， businesses distributing videos face hard times.
Which of the following， if true， would most seriously weaken the conclusion above？
（A） The market for video recorders would not be considered saturated until there was one in 80 percent of homes.
（B） Among the items handled by video distributors are many films specifically produced as video features.
（C） Few of the early buyers of video recorders raised any complaints about performance aspects of the new product.
（D） The early buyers of a novel product are always people who are quick to acquire novelties， but also often as quick to tire of them.
（E） In a shrinking market， competition always intensifies and marginal businesses fail.
7.This year the New Hampshire Division of Company X， set a new record for annual sales by that division. This record is especially surprising since the New Hampshire Division has the smallest potential market and the lowest sales of any of Company X's divisions.
Which of the following identifies a flaw in the logical coherence of the statement above？
（A） If overall sales for Company X were sharply reduced， the New Hampshire Division's new sales record is irrelevant to the company's prosperity.
（B） Since the division is competing against its own record， the comparison of its sales record with that of other divisions is irrelevant.
（C） If this is the first year that the New Hampshire Division has been last in sales among Company X's divisions， the new record is not surprising at all.
（D） If overall sales for Company X were greater than usual， it is not urprising that the New Hampshire Division was last in sales.
（E） Since the New Hampshire Division has the smallest potential market， it is not surprising that it had the lowest sales.
8.The average normal infant born in the United States weighs between twelve and fourteen pounds at the age of three months. Therefore， if a three-month-old child weighs only ten pounds， its weight gain has been below the United States average.Which of the following indicates a flaw in the reasoning above？
（A） Weight is only one measure of normal infant development.
（B） Some three-month-old children weigh as much as seventeen pounds.
（C） It is possible for a normal child to weigh ten pounds at birth.
（D） The phrase “ below average” does not necessarily mean insufficient.
（E）Average weight gain is not the same as average weight.
9.Politician：Fewer people are entering the labor market now than previously. If the economy grows，the demand for motivated and eduated people will far ou-tstrip thr supply. Some companies have already started to respond to this lab-or-maket situation by finding better ways to keep their current employee. Their concern is a sure indicator that the economy is growing.
Which of the following is the best criticism of the politician's reasoning？
（A）The fact that companies are making prudent preparations for a possible future development does not mean that this development is aleady taking place.
（B） The fact that some companies now try harder to keep their employee does not mean that they used to be indifferent to employee morale.
（C） The fact that demand will outstrip supply does not mean that there will be no supply at all.
10.Because postage rates are rising， Home Decorator magazine plans to maximize its profits by reducing by one half the number of issues it publishes each year.The quality of articles， the number of articles published per year， and the subscription price will not change. Market research shows that neither subscribers nor advertisers will be lost if the magazine's plan is instituted.
Which of the following， if true， provides the strongest evidence that the magazine's profits are likely to decline if the plan is instituted？
（A） With the new postage rates， a typical issue under the proposed plan would cost about one-third more to mail than a typical current issue would.
（B） The majority of the magazine's subscribers are less concerned about a possible reduction in the quantity of the magazine's articles than about a possible loss of the current high quality of its articles.
（C） Many of the magazine's long-time subscribers would continue their subscriptions even if the subscription price were increased.
（D） Most of the advertisers that purchase advertising space in the magazine will continue to spend the same amount on advertising per issue as they have in the past.
（E） Production costs for the magazine are expected to remain stable.
11.An overly centralized economy， not the changes in the climate， is responsible for the poor agricultural production in Country X since its new government came to power. Neighboring Country Y has experienced the same climatic conditions， but while agricultural production has been falling in Country X， it has been rising in Country Y.
Which of the following， if true， would most weaken the argument above？
（A） Industrial production also is declining in Country X.
（B） Whereas Country Y is landlocked， Country X has a major seaport.
（C） Both Country X and Country Y have been experiencing drought conditions.
（D） The crops that have always been grown in Country X are different from those that have always been grown in Country Y.
（E） Country X's new government instituted a centralized economy with the intention of ensuring an equitable distribution of goods.
12.Manager： Accounting and Billing are located right next to each other and the t-wo departments do similar kinds of work； yet expenditures for clerical supplies charged to Billing are much higher. Is Billing wasting supplies？ Head of Billing： Not at all.
Which of the following， if true， best supports the position of the Head ofBilling？
（A） There are more staff members in Accounting than in Billing.
（B） Two years ago， expenditures in Accounting for clerical supplies were the same as were expenditures that year in Billing for clerical supplies.
（C） The work of Billing now requires a wider variety of clerical supplies than it did in the past.
（D） Some of the paper-and-pencil work of both Accounting and Billing has been replaced by work done on computers.
（E） Members of Accounting found the clericalsupplies cabinet of Billing more convenient to go to for supplies than their own department's cabinet.
13.Some anthropologists study modern-day societies of foragers in an effort to learn about our ancient ancestors who were also foragers. A flaw in this strat-egy is that forager societies are extremely varied. Indeed， any forager society with which anthropologists are familiar has had considerable contact with mo-dern nonforager societies.
Which of the following， if true， would most weaken the criticism made above of the anthropologists' strategy？
（A） All forager societies throughout history have had a number of important features in common that are absent from other types of societies.
（B） Most ancient forager societies either dissolved or made a transition to another way of life.
（C） All anthropologists study one kind or another of modern-day society.
（D） Many anthropologists who study modern-day forager societies do not draw inferences about ancient societies on the basis of their studies.
（E） Even those modern-day forager societies that have not had significant contact with modern societies are importantly different from ancient forager societies.
14.In a study of the effect of color on productivity，50 of 100 factory workers were moved from their drab workroom to a brightly colored workroom.Both these workers and the 50 who remained in the drab workroom increased their prod-uctivity， probably as a result of the interest taken by researchers in the work of both groups during the study.Which of the following， if true， would cast most doubt upon the author's inter-pretation of the study results given above？
（A） The 50 workers moved to the brightly colored room performed precisely the same manufacturing task as the workers who remained in the drab workroom.
（B） The drab workroom was designed to provide adequate space for at most 65 workers.
（C） The 50 workers who moved to the brightly colored workroom were matched as closely as possible in age and level of training to the 50 workers who remained in the drab work-room.
（D） Nearly all the workers in both groups had volunteered to move to the brightly colored workroom.
（E） Many of the workers who moved to the brightly colored workroom reported that they liked the drab workroom as well as or better than they liked the brightly colored workroom.
15.A researcher discovered that people who have low levels of immune-system activity tend to score much lower on tests of mental health than do people with normal or high immune-system activity. The researcher concluded from this experiment that the immune system protects against mental illness as well as against physical disease.
The researcher's conclusion would be most seriously weakened if it were true that
（A） there was a one-year delay between the completion of a pilot study for the experiment and the initiation of the experiment itself.
（B） people's levels of immune-system activity are not affected by their use of medications.
（C） a few people with high immune-system activity had scores on the test of mental health that were similar to the scores of people who had normal immune-system activity.
（D） people who have low immune-system activtiy tend to contract more viral infections than do people with normal or high immune-system activitiy.
（E） high levels of stress first cause mental illness and then cause decreased immune-system activitiy in normal individuals
16.A researcher studying drug addicts found that， on average， they tend to manipulate other people a great deal more than nonaddicts do. The researcher concluded that people who frequently manipulate other people are likely to become addicts.
Which of the following， if true， most seriously weakens the researcher's conclusion？
（A） After becoming addicted to drugs， drug addicts learn to manipulate other people as a way of obtaining drugs.
（B） When they are imprisoned， drug addicts often use their ability to manipulate other people to obtain better living conditions.
（C） Some nonaddicts manipulate other people more than some addicts do.
（D） People who are likely to become addicts exhibit unusual behavior patterrns other than frequent manipulation of other people.
17.Advertisement：For sinus pain， three out of four hospitals give their patients Novex So when you want the most effective painkiller for sinus pain， Novex is the one to choose.
Which of the following， if true， most seriously ndermines the advertisement's argument？
（A） Some competing brands of painkillers are intended to reduce other kinds of pain in addition to sinus pain.
（B） Many hospitals that do not usually use Novex will do so for those patients who cannot tolerate the drug the hospitals usually use.
（C） Many drug manufacturers increase sales of their products to hospitals by selling these products to the hospitals at the lowest price the manufacturers can afford.
（D） Unlike some competing brands of painkillers， Novex is available from pharmacies without a doctor's prescription.
（E） In clinical trials Noxvex has been found more effective than competing brands of painkillers that have been on the market longer than Novex.
18.Hardin argued that grazing land held in common （that is， open to any user） would always be used less carefully than private grazing land. Each rancher would be tempted to overuse common land because the benefits would accrue to the individual， while the costs of reduced land quality that results from overuse would be spread among all users. But a study comparing 217 million acres of common grazing land with 433 million acres of private grazing land showed that the common land was in better condition.
The answer to which of the following questions would be most useful in evaluating the significance， in relation to Hardin's claim， of the study described above？
（A） Did any of the ranchers whose land was studied use both common and private land？
（B） Did the ranchers whose land was studied tend to prefer using common land over using private land for grazing？
（C） Was the private land that was studied of comparable quality to the common land before either was used for grazing？
（D） Were the users of the common land that was studied at least as prosperous as the users of the private land？
（E） Were there any owners of herds who used only common land， and no private land， for grazing？
19.Guitar strings often go “dead”-become less responsive and bright in tone-after a few weeks of intense use. A researcher whose son is a classical guitarist hypothesized that dirt and oil， rather than changes in the material properties of the string， were responsible.
Which of the following investigations is most likely to yield significant information that would help to evaluate the researcher's hypothesis？
（A） Determining if a metal alloy is used to make the strings used by classical guitarists
（B） Determining whether classical guitarists make their strings go dead faster than do folk guitarists
（C） Determining whether identical lengths of string， of the same gauge， go dead at different rates when strung on various brands of guitars.
（D） Determining whether a dead string and a new string produce different qualities of sound
（E） Determining whether smearing various substances on new guitar string cause them to go dead
key： BEAAB DBEAD DEABE ADCE
Which of the following， if true， most strongly supports the archaeologists' hypothesis？
（A） Bronze ceremonial drinking vessels that are often found in graves dating from years preceding and following A.D.365 were also found in several graves near Kourion.
（B） No coins minted after A.D.365 were found in Kourion， but coins minted before that year were found in abundance.
（C） Most modern histories of Cyprus mention that an earthquake occurred near the island in A.D.365.
（D） Several small statues carved in styles current in Cyprus in the century between A.D.300 and 400 were found in Kourion. （E） Stone inscriptions in a form of the Greek alphabet that was definitely used in Cyprus after A.D.365 were found in Kourion.
2.In Swartkans territory， archaeologists discovered charred bone fragments dating back 1 million years. Analysis of the fragments， which came from a variety of animals， showed that they had been heated to temperatures no higher than those produced in experimental campfires made from branches of white stink-wood， the most common tree around Swartkans.
Which of the following， if true， would， together with the information above， provide the best basis for the claim that the charred bone fragments are evidence of the use of fire by early hominids？
（A） The white stinkwood tree is used for building material by the present day inhabitants of Swartkans.
（B） Forest fires can heat wood to a range of temperatures that occur in campfires.
（C） The bone fragments were fitted together by the archaeologists to form the complete skeletons of several animals.
（D） Apart from the Swartkans discovery， there is reliable evidence that early hominids used fire as many as 500 thousand years ago.
（E） The bone fragments were found in several distinct layers of limestone that contained primitive cutting tools known to have been used by early hominids.
3.Black Americans are， on the whole， about twice as likely as White Americans to develop high blood pressure. This likelihood also holds for westernized Black Africans when compared to White Africans. Researchers have hypothesized that this predisposition in westernized Blacks may reflect an interaction between western high-salt diets and genes that adapted to an environmental scarcity of salt.
Which of the following statements about present-day， westernized Black Africans， if true， would most tend to confirm the researchers' hypothesis？
（A） The blood pressures of those descended from peoples situated throughout their history in Senegal and Gambia， where salt was always available， are low.
（B） The unusually high salt consumption in certain areas of Africa represents a serious health problem.
（C） Because of their blood pressure levels， most White Africans have markedly decreased their salt consumption.
（D） Blood pressures are low among the Yoruba， who， throughout their history， have been situated far inland from sources of sea salt and far south of Saharan salt mines.
（E） No significant differences in salt metabolism have been found between those people who have had salt available throughout their history and those who have not.
4.Two decades after the Emerald River Dam was built， none of the eight fish species native to the Emerald River was still reproducing adequately in the river below the dam. Since the dam reduced the annual range of water temperature in the river below the dam from 50 degrees to 6 degrees， scientists have hypothesized that sharply rising water temperatures must be involved in signaling the native species to begin the reproductive cycle.
Which of the following statements， if true， would most strengthen the scientists' hypothesis？
（A） The native fish species were still able to reproduce only in side streams of the river below the dam where the annual temperature range remains approximately 50 degrees.
（B） Before the dam was built， the Emerald River annually overflowed its banks， creating backwaters that were critical breeding areas for the native species of fish.
（C） The lowest recorded temperature of the Emerald River before the dam was built was 34 degrees， whereas the lowest recorded temperature of the river after the dam was built has been 43 degrees.
（D）Nonnative species of fish， introduced into the Emerald River after the dam was built， have begun competing with the declining native fish species for food and space.
（E） Five of the fish species native to the Emerald River are not native to any other river in North America.
5. An advertisement designed to convince readers of the great durability of automobiles manufactured by the Deluxe Motor Car Company cites as evidence the fact that over half of all automobiles built by the company since 1970 are still on the road today， compared to no more than a third for any other manufacturer.
Which of the following， if true， most strongly supports the advertisement's argument？
（A） After taking inflation into account， a new Deluxe automobile costs only slightly more than a new model did in 1970.
（B） The number of automobiles built by Deluxe each year has not increased sharply since 1970.
（C） Owners of Deluxe automobiles typically keep their cars well maintained.
（D） Since 1970， Deluxe has made fewer changes in the automobiles it manufactures than other car companies have made in their automobiles.
（E） Deluxe automobiles have been selling at relatively stable prices in recent years.
6.Six months or so after getting a video recorder， many early buyers apparently lost interest in obtaining videos to watch on it. The trade of businesses selling and renting videos is still buoyant， because the number of homes with video recorders is still growing. But clearly， once the market for video recorders is saturated， businesses distributing videos face hard times.
Which of the following， if true， would most seriously weaken the conclusion above？
（A） The market for video recorders would not be considered saturated until there was one in 80 percent of homes.
（B） Among the items handled by video distributors are many films specifically produced as video features.
（C） Few of the early buyers of video recorders raised any complaints about performance aspects of the new product.
（D） The early buyers of a novel product are always people who are quick to acquire novelties， but also often as quick to tire of them.
（E） In a shrinking market， competition always intensifies and marginal businesses fail.
7.This year the New Hampshire Division of Company X， set a new record for annual sales by that division. This record is especially surprising since the New Hampshire Division has the smallest potential market and the lowest sales of any of Company X's divisions.
Which of the following identifies a flaw in the logical coherence of the statement above？
（A） If overall sales for Company X were sharply reduced， the New Hampshire Division's new sales record is irrelevant to the company's prosperity.
（B） Since the division is competing against its own record， the comparison of its sales record with that of other divisions is irrelevant.
（C） If this is the first year that the New Hampshire Division has been last in sales among Company X's divisions， the new record is not surprising at all.
（D） If overall sales for Company X were greater than usual， it is not urprising that the New Hampshire Division was last in sales.
（E） Since the New Hampshire Division has the smallest potential market， it is not surprising that it had the lowest sales.
8.The average normal infant born in the United States weighs between twelve and fourteen pounds at the age of three months. Therefore， if a three-month-old child weighs only ten pounds， its weight gain has been below the United States average.Which of the following indicates a flaw in the reasoning above？
（A） Weight is only one measure of normal infant development.
（B） Some three-month-old children weigh as much as seventeen pounds.
（C） It is possible for a normal child to weigh ten pounds at birth.
（D） The phrase “ below average” does not necessarily mean insufficient.
（E）Average weight gain is not the same as average weight.
9.Politician：Fewer people are entering the labor market now than previously. If the economy grows，the demand for motivated and eduated people will far ou-tstrip thr supply. Some companies have already started to respond to this lab-or-maket situation by finding better ways to keep their current employee. Their concern is a sure indicator that the economy is growing.
Which of the following is the best criticism of the politician's reasoning？
（A）The fact that companies are making prudent preparations for a possible future development does not mean that this development is aleady taking place.
（B） The fact that some companies now try harder to keep their employee does not mean that they used to be indifferent to employee morale.
（C） The fact that demand will outstrip supply does not mean that there will be no supply at all.
10.Because postage rates are rising， Home Decorator magazine plans to maximize its profits by reducing by one half the number of issues it publishes each year.The quality of articles， the number of articles published per year， and the subscription price will not change. Market research shows that neither subscribers nor advertisers will be lost if the magazine's plan is instituted.
Which of the following， if true， provides the strongest evidence that the magazine's profits are likely to decline if the plan is instituted？
（A） With the new postage rates， a typical issue under the proposed plan would cost about one-third more to mail than a typical current issue would.
（B） The majority of the magazine's subscribers are less concerned about a possible reduction in the quantity of the magazine's articles than about a possible loss of the current high quality of its articles.
（C） Many of the magazine's long-time subscribers would continue their subscriptions even if the subscription price were increased.
（D） Most of the advertisers that purchase advertising space in the magazine will continue to spend the same amount on advertising per issue as they have in the past.
（E） Production costs for the magazine are expected to remain stable.
11.An overly centralized economy， not the changes in the climate， is responsible for the poor agricultural production in Country X since its new government came to power. Neighboring Country Y has experienced the same climatic conditions， but while agricultural production has been falling in Country X， it has been rising in Country Y.
Which of the following， if true， would most weaken the argument above？
（A） Industrial production also is declining in Country X.
（B） Whereas Country Y is landlocked， Country X has a major seaport.
（C） Both Country X and Country Y have been experiencing drought conditions.
（D） The crops that have always been grown in Country X are different from those that have always been grown in Country Y.
（E） Country X's new government instituted a centralized economy with the intention of ensuring an equitable distribution of goods.
12.Manager： Accounting and Billing are located right next to each other and the t-wo departments do similar kinds of work； yet expenditures for clerical supplies charged to Billing are much higher. Is Billing wasting supplies？ Head of Billing： Not at all.
Which of the following， if true， best supports the position of the Head ofBilling？
（A） There are more staff members in Accounting than in Billing.
（B） Two years ago， expenditures in Accounting for clerical supplies were the same as were expenditures that year in Billing for clerical supplies.
（C） The work of Billing now requires a wider variety of clerical supplies than it did in the past.
（D） Some of the paper-and-pencil work of both Accounting and Billing has been replaced by work done on computers.
（E） Members of Accounting found the clericalsupplies cabinet of Billing more convenient to go to for supplies than their own department's cabinet.
13.Some anthropologists study modern-day societies of foragers in an effort to learn about our ancient ancestors who were also foragers. A flaw in this strat-egy is that forager societies are extremely varied. Indeed， any forager society with which anthropologists are familiar has had considerable contact with mo-dern nonforager societies.
Which of the following， if true， would most weaken the criticism made above of the anthropologists' strategy？
（A） All forager societies throughout history have had a number of important features in common that are absent from other types of societies.
（B） Most ancient forager societies either dissolved or made a transition to another way of life.
（C） All anthropologists study one kind or another of modern-day society.
（D） Many anthropologists who study modern-day forager societies do not draw inferences about ancient societies on the basis of their studies.
（E） Even those modern-day forager societies that have not had significant contact with modern societies are importantly different from ancient forager societies.
14.In a study of the effect of color on productivity，50 of 100 factory workers were moved from their drab workroom to a brightly colored workroom.Both these workers and the 50 who remained in the drab workroom increased their prod-uctivity， probably as a result of the interest taken by researchers in the work of both groups during the study.Which of the following， if true， would cast most doubt upon the author's inter-pretation of the study results given above？
（A） The 50 workers moved to the brightly colored room performed precisely the same manufacturing task as the workers who remained in the drab workroom.
（B） The drab workroom was designed to provide adequate space for at most 65 workers.
（C） The 50 workers who moved to the brightly colored workroom were matched as closely as possible in age and level of training to the 50 workers who remained in the drab work-room.
（D） Nearly all the workers in both groups had volunteered to move to the brightly colored workroom.
（E） Many of the workers who moved to the brightly colored workroom reported that they liked the drab workroom as well as or better than they liked the brightly colored workroom.
15.A researcher discovered that people who have low levels of immune-system activity tend to score much lower on tests of mental health than do people with normal or high immune-system activity. The researcher concluded from this experiment that the immune system protects against mental illness as well as against physical disease.
The researcher's conclusion would be most seriously weakened if it were true that
（A） there was a one-year delay between the completion of a pilot study for the experiment and the initiation of the experiment itself.
（B） people's levels of immune-system activity are not affected by their use of medications.
（C） a few people with high immune-system activity had scores on the test of mental health that were similar to the scores of people who had normal immune-system activity.
（D） people who have low immune-system activtiy tend to contract more viral infections than do people with normal or high immune-system activitiy.
（E） high levels of stress first cause mental illness and then cause decreased immune-system activitiy in normal individuals
16.A researcher studying drug addicts found that， on average， they tend to manipulate other people a great deal more than nonaddicts do. The researcher concluded that people who frequently manipulate other people are likely to become addicts.
Which of the following， if true， most seriously weakens the researcher's conclusion？
（A） After becoming addicted to drugs， drug addicts learn to manipulate other people as a way of obtaining drugs.
（B） When they are imprisoned， drug addicts often use their ability to manipulate other people to obtain better living conditions.
（C） Some nonaddicts manipulate other people more than some addicts do.
（D） People who are likely to become addicts exhibit unusual behavior patterrns other than frequent manipulation of other people.
17.Advertisement：For sinus pain， three out of four hospitals give their patients Novex So when you want the most effective painkiller for sinus pain， Novex is the one to choose.
Which of the following， if true， most seriously ndermines the advertisement's argument？
（A） Some competing brands of painkillers are intended to reduce other kinds of pain in addition to sinus pain.
（B） Many hospitals that do not usually use Novex will do so for those patients who cannot tolerate the drug the hospitals usually use.
（C） Many drug manufacturers increase sales of their products to hospitals by selling these products to the hospitals at the lowest price the manufacturers can afford.
（D） Unlike some competing brands of painkillers， Novex is available from pharmacies without a doctor's prescription.
（E） In clinical trials Noxvex has been found more effective than competing brands of painkillers that have been on the market longer than Novex.
18.Hardin argued that grazing land held in common （that is， open to any user） would always be used less carefully than private grazing land. Each rancher would be tempted to overuse common land because the benefits would accrue to the individual， while the costs of reduced land quality that results from overuse would be spread among all users. But a study comparing 217 million acres of common grazing land with 433 million acres of private grazing land showed that the common land was in better condition.
The answer to which of the following questions would be most useful in evaluating the significance， in relation to Hardin's claim， of the study described above？
（A） Did any of the ranchers whose land was studied use both common and private land？
（B） Did the ranchers whose land was studied tend to prefer using common land over using private land for grazing？
（C） Was the private land that was studied of comparable quality to the common land before either was used for grazing？
（D） Were the users of the common land that was studied at least as prosperous as the users of the private land？
（E） Were there any owners of herds who used only common land， and no private land， for grazing？
19.Guitar strings often go “dead”-become less responsive and bright in tone-after a few weeks of intense use. A researcher whose son is a classical guitarist hypothesized that dirt and oil， rather than changes in the material properties of the string， were responsible.
Which of the following investigations is most likely to yield significant information that would help to evaluate the researcher's hypothesis？
（A） Determining if a metal alloy is used to make the strings used by classical guitarists
（B） Determining whether classical guitarists make their strings go dead faster than do folk guitarists
（C） Determining whether identical lengths of string， of the same gauge， go dead at different rates when strung on various brands of guitars.
（D） Determining whether a dead string and a new string produce different qualities of sound
（E） Determining whether smearing various substances on new guitar string cause them to go dead
key： BEAAB DBEAD DEABE ADCE