1.Drug companies lose money when manufacturing drugs that cure those suffering from rare diseases because selling a drug to only a few people usually does not recoup manufacturing expenses.Therefore，a company manufacturing any of the drugs that cure those suffering from loxemia，an extremely rare disease，will undoubtedly lose money.
Which of the following，if true，most seriously weakens the conclusion above?
(A)Several drugs that cure those suffering from loxemia also cure those suffering from very common illnesses.
(B)Most of those who contract loxemia also con-tract another illness concurrently.
(C)Most of the drug companies that manufacture drugs that cure rare diseases do not manufac-ture drugs that cure loxemia.
(D)A sizable number of people are afflicted with one or another rare disease even though each rare disease afflicts only a small number of people.
(E)The larger the amount of a drug that is manu-factured，the lower the manufacturing expense for each unit of the drug that is produced.
2.The tomb of a warrior killed in 1501 bears a sculpted portrait depicting him dressed for battle.Some his-torians attribute the portrait to an artist from that century，but of the many references to the tomb in surviving documents，none that predates the 1800's mentions the portrait.The portrait is therefore more likely the work of a much later artist.
Which of the following，if true，would also support the conclusion of the argument if substituted for the evidence given concerning the portrait?
(A)The portrait of the warrior was commissioned by the family of the warrior's widow.
(B)References in surviving documents mention that an artist was paid in 1525 for an unspecified number of works for the church in which the tomb is located
(C)The warrior is depicted in the portrait as wearing boots made of a material not used for boots until the 1700's.
(D)Some other art treasures from the church in which the tomb is located have been reliable dated to the 1400's.
(E)The portrait of the warrior on the tomb strongly resembles a portrait of him known to have been completed during his lifetime.
3.Scientist：More than 1，000 large asteroids regularly cross the Earth's path.Even though the probabil-ity of one colliding with the Earth is extremely slight，we should do whatever we can to reduce that probability since any such collision would be catastrophic.The best way to avoid such a disaster is to deflect the asteroids.The only known way of deflecting asteroids is by hitting them with nuclear weapons that would be stored in space stations.
The scientist's claims are structured so as to lead to which of the following conclusions?
(A)Nuclear technology is the only technology that can plausibly be used to prevent natural catastrophes.
(B)Nuclear weapons should be deployed in space.
(C)No catastrophe has yet been caused by the collision of an asteroid with the Earth.
(D)The 1，000 large asteroids that cross the Earth's path pose only an extremely slight risk of colliding with the Earth.
(E)There is currently no acceptable use to which nuclear weapons can be put，aside from pro-tecting the Earth from asteroids.
4.It has long been thought that high levels of the hor-mone testosterone contribute to the onset of heart disease in men.However，this view cannot be correct，since men who have heart disease typically show significantly lower levels of testosterone than do men who have not had heart disease.
The argument above assumes which of the following?
(A)Many men who have never had heart disease have unusually low levels of testosterone.
(B)Having heart disease does not significantly lower the level of testosterone in men.
(C)Levels of hormones other than testosterone significantly affect the likelihood that a man will develop heart disease.
(D)Heart disease and lowered testosterone levels in men are the effects of a single common cause.
(E)High levels of testosterone have never been thought to contribute to a serious disease other than heart disease.
5.People who engage in scuba diving are healthier，on average，than people who do not engage in this activity.Therefore，scuba diving tends to promote improved health.
The argument is most vulnerable to criticism on the grounds that it
(A)presupposes that everyone who takes up scuba diving does so solely for health reasons
(B)leads to a further and falsifiable conclusion that no one can achieve good health without engaging in scuba diving
(C)fails to point out that a small number of people are seriously injured in scuba diving accidents each year
(D)treats a precondition for improving one's health as though it were something that by itself could ensure good health
(E)overlooks the possibility that people generally do not take up scuba diving unless they are in good health
6.Which of the following most logically completes the argument below?In recent years，the proportion of car buyers who buy new cars rather than used cars has declined.Some consumers have attributed this change to an increase in new-car prices.As evidence of the price increase，they cite figures that show that，even adjusting for inflation，the price that the buyer of a new car pays，on average，is far higher now than a few years ago.
This evidence is unpersuasive，however，because
(A)the value of a car that is bought new declines much more rapidly than does the value of a car that is bought used
(B)after someone has bought a car，it might be several years before that person next buys a car
(C)a decline in the proportion of car buyers who buy new cars must necessarily mean that the proportion who buy used cars has increased
(D)the relative increase in used-car sales might be explained by the decisions of only a small proportion of all car buyers
(E)the change in the average price paid for a new car could result solely from more people's rejecting inexpensive new cars in favor of used cars
7.In Bassaria a group of that country's most senior judges has criticized the uniform mandatory sentences recently introduced for certain specific crimes.The judges argue that such sentences，by depriving them of all discretion in setting sentences，make it impos-sible for them to consider either aggravating or exten-uating circumstances and so make it impossible to achieve true justice―the fitting of the severity of the punishment to the gravity of the particular crime.
Which of the following，if true，provides the strongest evidence for the claim that in Bassaria the newly introduced mandatory sentences are not necessarily a change for the worse with respect to achieving true justice as defined in the argument?
(A)Before mandatory sentencing，judges in eastern Bassaria imposed strikingly different sentences from those in western Bassaria for equally grave instances of the same kind of offense.
(B)In Bassaria the frequency of crimes that have been made subject to mandatory sentences is lower now than it was just prior to the intro-duction of mandatory sentencing.
(C)The law introducing mandatory sentences was passed in the legislature of Bassaria by a large majority and is unlikely to be repealed in the foreseeable future.
(D)There used to be a wide difference between the minimum and the maximum sentences allowed by law in cases of crimes now subject to man-datory sentences.
(E)In Bassaria judges are appointed for life and are thus not easily influenced by political pressure groups.
8.Each of two particular inspection systems that are based on different principles would detect all product flaws but would also erroneously reject three percent of flawless products.Assuming there is no overlap between the products erroneously rejected by the two systems and also no interference between the systems if both operate，using both systems and rejecting only those products found flawed by both would be a way of avoiding all erroneous rejections.
Which of the following most precisely characterizes the reasoning in the argument?
(A)The reasoning is conclusive，that is，the conclusion cannot be false if the statements offered in its support are true.
(B)The reasoning is strong but not conclusive，if the statements offered in support of the conclusion are true，they provide good grounds for that conclu-sion，though it is possible that additional infor-mation might weaken the argument.
(C)The reasoning is weak; the statements offered in support of the conclusion，though relevant to it，by themselves provide at best inadequate grounds for the conclusion.
(D)The reasoning is flawed in that the conclusion is no more than a paraphrase of one of the pieces of evidence offered in its support.
(E)The reasoning is flawed in that the argument treats evidence that a factor is necessary to bring about an event as if it were evidence that the factor is sufficient to bring about that event.
9.In recent years，there has been a dramatic decline in the population of the shrike，a predatory bird that inhabits flat land，such as farms and pastures.Some ornithologists hypothesize that this decline is due to the introduction of new，more effective pesticides to control the insect species on which shrikes prey.
The answer to which of the following questions is NOT relevant to evaluating the ornithologists' hypothesis?
(A)Was there a decline in the shrike population before the new pesticides were first used?
(B)Have shrike populations declined significantly in those habitats where the new pesticides have not been used?
(C)Have the new pesticides more significantly reduced the population of insect species on which shrikes prey than did the pesticides previously used?
(D)Are insects that have consumed the new pesti-cides more toxic to the shrikes that eat those insects than were insects that consumed the less effective pesticides?
(E)Are the new pesticides considered by most people to be less harmful to the environment than the old pesticides were considered to be?
10.Census data for Prenland show that unmarried Prenlandic men in their thirties outnumber unmarried Prenlandic women in that age group by about ten to One.Most of these men do wish to marry.Clearly，however，unless many of them marry women who are not Prenlandic，all but a minority will remain unmarried.
The argument makes which of the following assump-tions?
(A)Emigration from Preland is more common among women than among men.
(B)A greater proportion of Prelandic women in their thirties than of Prenlandic men of the same age would prefer to remain unmarried.
(C)It is unlikely that many of these unmarried Prenlandic men will marry women more than a few years older than themselves.
(D)Prenland has a high rate of divorce.
(E)Most of the unmarried Prenlandic men are unwilling to marry women who are not Prenlandic.
11.Certain extremely harmful bacteria found only in sewage are difficult to detect directly.Testing for E.coli，an easily detected and less harmful type of bacteria，in ocean water would be a reliable way of determining whether or not these more harmful bac-teria are present，since ocean water contains E.Coli only if the water is contaminated with sewage that contains the harmful bacteria.
Which of the following，if true，most seriously weakens the argument?
(A)There are many different strains of the E.coli bacteria，and only some of these strains are harmful.
(B)Some types of bacteria found in sewage are neither disease-causing nor difficult to detect directly.
(C)Some of the types of bacteria found in sewage along with E.coli are not harmful to people unless the bacteria are ingested in large quantities.
(D)E.coli dies out much more quickly than some of the more harmful bacteria found in sewage and then can no longer be easily detected.
(E)Some of the types of bacteria found in sewage along with E.coli reproduce at a slower rate than E.coli.
12.The organizers of tomorrow's outdoor concert announced that it will go on tomorrow on schedule unless bad weather is forecast or too few advance tickets are sold.If the concert is canceled，refunds will be made to ticket holders.Since some ticket holders have already been issued refunds even though more than enough advance tickets were sold，it must be the case that bad weather is forecast.
Which of the following is an error of reasoning con-tained in the argument?
(A)It proceeds as if a condition，which by itself is enough to guarantee a certain result，is the only condition under which that result would occur.
(B)It bases a conclusion that is known to require two conditions on evidence that bears on only one of those conditions.
(C)It explains one event as being caused by another event，even though both events must actually have been caused by some third，unidentified event.
(D)It treats evidence for the absence of one condi-tion under which a circumstance would occur as conclusive evidence that that circumstance will not occur.
(E)Evidence given to support the conclusion actually undermines it.
13.Although the prevailing supposition has been that it is too hot for microorganisms to survive deep below the Earth's surface，some scientists argue that there are living communities of microorganisms there that have been cut off from surface life for millions of years.These scientists base their argument on the discovery of living microorganisms in samples of material that were taken from holes drilled as deep as 1.74 miles.
The scientists' argument depends on which of the fol-lowing assumptions?
(A)The microorganisms brought up were of a species that is related to those previously known to science.
(B)No holes have been drilled into the Earth's surface to a distance deeper than 1.74 miles
(C)The microorganisms did not come from surface soil that came into contact with the drilling equipment.
(D)The stratum from which the samples came has been below the surface of the Earth ever since the Earth came into existence.
(E)The temperature at the bottom of the holes drilled was not significantly hotter than that of the hottest spots on the Earth's surface.
14.For 20 years all applicants for jobs as technicians at EquipCorp were required to demonstrate that they could operate and repair the machinery that was central to EquipCorp's manufacturing business.Now，however，that particular machinery is obsolete，and very different machinery fills the central role.Therefore，the old requirement is no longer a useful method for evaluating whether applicants for jobs as technicians at EquipCorp have the skills necessary for the job.
Which of the following，if true，most strengthens the argument?
(A)The machinery that is now obsolete was used by a large number of manufacturing companies before it became obsolete.
(B)Among the people already holding jobs as tech-nicians at Equip Corp，those who are most skillful at operating the new machinery had been some of the least skillful at operating the old machinery
(C)Most people applying for jobs as technicians today have much broader skills than did people applying for jobs as technicians 20 years ago.
(D)The skills required to operate and repair the obsolete machinery are useful in operating and maintaining many other types of machinery at EquipCorp that are not obsolete.
(E)Much of the machinery that EquipCorp now uses in manufacturing is very likely to become obsolete within the next 20 years.
GRE考試邏輯題參考答案：A C B B E E A A E C D A C B