"Surprising" Phenomenon
Why do many cedars on cliff faces, which are relatively undernourished, live longer than cedars in forests?
Objective
A hypothesis explaining this discrepancy must state a key difference between cedars on cliff faces and cedars in forests. This difference must result in many cedars on cliff faces living longer than most cedars in forests.
A
The conditions on cliff faces are similar to those in most other places where there are few tall trees.
This does not explain the relative longevity of cedars on cliff faces. It suggests that environmental conditions cause cedars on cliff faces to grow shorter, but states no relationship between a cedar's height and its life span.
B
In areas where eastern white cedars grow, forest fires are relatively frequent, but fires cannot reach cliff faces.
This explains why cedars on cliff faces more often live to old age. Forest fires kill many cedars in forests, but do not reach cedars on cliff faces, so cedars in forests are exposed to a survival risk that cedars on cliff faces are not.
C
Trees that are older than a few hundred years start to lose the protective outer layer of their bark.
This is not a difference between cedars in forests and cedars on cliff faces. If all cedars lose their bark’s outer layer in old age, then cedars in both places should be equally affected.
D
The roots of cedars on cliff faces lodge in cracks in the cliff, and once the roots are so large that they fill a crack, the tree is unable to grow any taller.
This explains why cedars on cliff faces are shorter, but not why more of them grow old. It states no relationship between the height of a tree and its longevity.
E
Eastern white cedar wood is too soft to be used for firewood or modern buildings, but it is occasionally used to make furniture.
This rules out a possible explanation, rather than provide one. It implies that cedars are only infrequently harvested for wood, casting doubt on the possibility that cedars in forests are killed in large numbers by humans.
"Surprising" Phenomenon
Why is the most common bird in the marsh the least commonly spotted?
Objective
The correct answer must fail to explain why this marsh hen is seen less frequently. Every wrong answer will identify a difference between the marsh hen and the other species—such as a difference in appearance, location, or behavior—that explains this discrepancy.
A
The coloration of the marsh hen blends in particularly well with the marsh grass where the marsh hen nests.
This explains why these marsh hens are seen less frequently than other species. Because of their special camouflage, they are spotted rarely even though they are common.
B
The marsh hen’s call is harsh and repetitive, whereas the calls of many other marsh birds are pleasant and melodious.
This does not explain why this marsh hen is spotted less frequently than other species. A harsh repetitive call would attract attention and make the marsh hen more likely to be spotted, not less.
C
Unlike many small marsh birds, which dash along the banks of the marsh, the marsh hen remains completely still for long periods of time.
This explains why this marsh hen is seen less frequently than other species. The others move around the banks, making them visible to human visitors, while the marsh hen is stationary and therefore harder to spot.
D
Many marsh birds are most active during daylight hours, but the marsh hen is usually most active at night.
This explains why the marsh hen is seen less frequently than other species of birds. It is active at night, when the cover of darkness makes it difficult to see.
E
Although many small marsh birds fly in groups to several feeding areas each day, the marsh hen tends to be solitary and flies only when it is in danger.
This explains why the marsh hen is seen less frequently than other species of birds. Other species travel often and in groups, making them more easily sighted by visitors, while the marsh hen is more solitary and sedentary.
Michiko: But the idea of the modern Olympics is to showcase the world’s finest athletes, regardless of their backgrounds or resources. Hence, professionals should be allowed to compete.
Speaker 1 Summary
Juan thinks that having professional athletes compete in the Olympics violates the spirit of fairness underpinning the games. Why? Because professional athletes will likely not be seriously challenged by amateurs. This is further backed up by the fact that professionals generally have more resources than amateurs.
Speaker 2 Summary
Michiko argues that professional athletes should be allowed to compete in the Olympics. Why? Because the point of the Olympics is to display the best athletes in the world, even if they’re the best because they have more resources.
Objective
We need to find a point of disagreement. Juan and Michiko disagree about the most important principle behind the Olympics: Juan thinks it’s fairness, but Michiko thinks it’s showcasing excellence.
A
whether the participation of both amateur and professional athletes is in accord with the ideals of the modern Olympics
Juan thinks that the participation of professionals is not in accord, but Michiko thinks it is—this is the disagreement. This is because Juan thinks that fairness is the key ideal of the Olympics, but Michiko thinks the Olympics are about displaying athletic excellence.
B
whether both amateur and professional athletes competed in the ancient Olympic games upon which the modern Olympics are based
Juan claims in passing that amateurs and professionals did not both compete in the ancient Olympics, but Michiko neither agrees nor disagrees. Michiko just talks about the modern Olympics.
C
whether the athletes who compete in the modern Olympics are the world’s finest
Neither speaker actually says whether modern Olympic athletes are the world’s best or not. Michiko indicates that they should be the best, but even then doesn’t discuss whether that reflect reality.
D
whether any amateur athletes have the financial or material resources that are available to professional athletes
Neither speaker makes an absolute claim that no amateurs have the same resources as professionals. Juan says that amateurs “rarely” have those resources, and Michiko says nothing at all about who has resources.
E
whether governments sponsor professional as well as amateur athletes in the modern Olympics
Neither speaker mentions government sponsorship of athletes at all.
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that galanin makes rats crave fatty foods. Why? Because an experiment showed a correlation: rats who preferred fatty foods also had higher galanin concentrations in their brains.
Notable Assumptions
The author assumes the correlation results from one particular causation: that lots of brain galanin causes rats to crave fatty foods. This means assuming there’s no other cause for that correlation, such as the reverse causation: that eating fatty foods causes galanin to build up in rats’ brains.
A
The craving for fatty foods does not invariably result in a rat’s choosing those foods over lean foods.
This doesn’t affect the argument. Rats could have “consistently” chosen fatty food without choosing it every single time.
B
The brains of the rats that consistently chose to eat fatty foods did not contain significantly more fat than did the brains of rats that consistently chose lean foods.
This is irrelevant. The author makes no claim about fat inside the rats’ brains—only the fat in their food and the galanin in their brains.
C
The chemical components of galanin are present in both fatty foods and lean foods.
This doesn’t mean the fatty and lean diets contained similar amounts of galanin. This is fully compatible with the reverse causation: the rats who preferred fatty foods simply consumed more galanin in their diets.
D
The rats that preferred fatty foods had the higher concentrations of galanin in their brains before they were offered fatty foods.
This strengthens the argument by casting doubt on an alternative explanation. It makes the reverse causation—that rats had lots of galanin in their brains because of their high fat intake—less likely.
E
Rats that metabolize fat less efficiently than do other rats develop high concentrations of galanin in their brains.
This detail is compatible with the conclusion, but it doesn’t strengthen the argument. It’s just as compatible with the reverse causation: rats who metabolize fat less efficiently crave fattier foods, and that higher fat consumption causes galanin to build up in their brains.
Summarize Argument: Phenomenon-Hypothesis
The author concludes that to be safe from attack, people should stay home whenever possible. Why? Because news media cover more violent crime than they used to, meaning violent crime has increased dramatically.
Notable Assumptions
The author assumes media cover more violent crime because that crime is much more prevalent, and not for any other reason. In addition, he assumes people are less likely to be victims of violent crime when they stay at home.
A
Newspapers and televised news programs have more comprehensive coverage of violent crime than newspapers did in the old days.
This challenges the assumption that violent crime receives more coverage because it’s out of control. Since media today cover crime more comprehensively, an increase in coverage does not necessarily mean an increase in crime.
B
National data show that violent crime is out of control everywhere, not just in the author’s city.
This expands the scope of the conclusion, but provides no reason to question it. It implies people should stay home across the entire country, not just in the author’s city.
C
Police records show that people experience more violent crimes in their own neighborhoods than they do outside their neighborhoods.
This doesn’t say people are more likely to experience violent crime when they are at home. The author recommends people stick to their homes, not stick to their own neighborhoods when they go out.
D
Murder comprised a larger proportion of violent crimes in the old days than it does today.
This doesn’t say murder rates have decreased. It’s possible other types of violent crime have simply increased more than the murder rate.
E
News magazines play a more important role today in informing the public about crime than they did in the old days.
This doesn’t say newspapers and televised news over-report violent crime. News magazines may report the same amount of violent crime, even if that reporting is more important than it used to be.
Summarize Argument: Phenomenon-Hypothesis
The researchers hypothesize that most marmosets become left-handed because they imitate their parents as babies. Why? Because infant marmosets are known to imitate frequently.
Notable Assumptions
The researchers assume there’s no alternative or additional explanation accounting for the prevalence of left-handedness among marmosets. In particular, they assume baby marmosets tend to imitate their parents, and that genetic factors don’t determine a marmoset’s handedness.
A
A study conducted on adult marmosets revealed that many were right-handed.
This doesn’t affect the researchers’ argument. It’s stated only that “[s]ignificantly more” marmosets are left-handed than right-handed, which is compatible with the existence of many right-handed marmosets, provided there are also lots of left-handed marmosets out there.
B
Right-handed marmosets virtually all have at least one sibling who is left-handed.
This weakens the researchers’ argument. It implies left-handed and right-handed marmosets are frequently raised by the same parents, making it less likely that marmosets tend to acquire the same handedness as their parents.
C
According to the study, 33 percent of marmosets are ambidextrous, showing equal facility using either their left hand or their right hand.
This doesn’t affect the researchers’ argument. It doesn’t change the relative prevalence of left-handed marmosets, nor does it imply the researchers are basing their hypothesis on faulty evidence.
D
Ninety percent of humans are right-handed, but those who are left-handed are likely to have at least one left-handed parent.
This implies humans tend to acquire their handedness from their parents, not that humans—or marmosets—acquire their handedness through imitation. There are many reasons, besides their tendency to imitate, why marmosets might, unlike humans, tend to be left-handed.
E
Marmosets raised in captivity with right-handed adult marmosets to whom they are not related are more likely to be right-handed than left-handed.
This supports the researchers’ hypothesis that handedness is developed through imitation, rather than solely genetic or environmental factors. It implies baby marmosets tend to acquire their handedness from other, nearby marmosets—not just from genetic relatives.
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that a new anticollision device is responsible for the sudden disappearance of information from air traffic controllers’ screens. This is based on the observation that over the last two years, the anticollision device has become more popular, while at the same time, the information disappearances have become more frequent.
Notable Assumptions
The author assumes that just because there’s a correlation between the use of the new anticollision device and information disappearing from air traffic controllers’ screens, the former must be causally contributing to the latter. This means that the author assumes there isn’t some other cause for the disappearing information.
A
The new anticollision device has already prevented a considerable number of mid-air collisions.
This does not weaken the argument, because it’s totally unrelated to the author’s hypothesis. The author isn’t saying we should stop using the anticollision device, just that it’s interfering with air traffic control information. This isn’t at all relevant to that claim.
B
It was not until the new anticollision device was introduced that key information first began disappearing suddenly from controllers’ screens.
This does not weaken the argument. In fact, it may even strengthen the argument by establishing a stronger temporal connection between the use of the new device and the information disappearance.
C
The new anticollision device is scheduled to be moved to a different frequency within the next two to three months.
This does not weaken the argument, because it doesn’t give us any reason to believe that the device may not interfere with air traffic control. If the frequency had been switched but information kept disappearing, that could weaken—but that’s not what this says.
D
Key information began disappearing from controllers’ screens three months before the new anticollision device was first tested.
This weakens the argument by undermining the temporal link between the use of the new device and the disappearing information. It still doesn’t tell us the true cause, but if the information was disappearing without the device ever being used, there must be another cause.
E
The sudden disappearance of key information from controllers’ screens has occurred only at relatively large airports.
This does not weaken the argument. We don’t know enough about how frequently the disappearances happen, how many planes use the new device, and so on, for this to be helpful. As it is, this doesn’t tell us anything about whether the new device truly causes interference.
Speaker 1 Summary
Some writers explain Stalin’s misdeeds by characterizing his sanity during his later years as “paranoia” and “morbid suspiciousness.” However, Stalin’s cruelty was not more apparent during his later years than it was during the earlier periods of his rule. “Morbid suspiciousness” is a required characteristic for tyrants, because without it they would not remain in power.
Speaker 2 Summary
Objective
We need a statement that the critic and writers disagree on. They disagree whether certain characteristics of Stalin could explain why he was such a cruel leader. The writers think that Stalin’s characteristics could explain his misdeeds, while the critic thinks that Stalin was always a cruel leader.
A
whether Stalin should be held guilty of the cruel deeds attributed to him
Neither speaker expresses an opinion on this statement. We don’t know whether either speaker believes Stalin should be held guilty.
B
whether Stalin’s cruel misdeeds provide evidence of morbid suspiciousness
Neither speaker expresses an opinion on this statement. The writers would think the opposite relationship is true. For the writers, Stalin’s morbid suspiciousness explain his cruel misdeeds.
C
whether it is Stalin’s state of paranoia or rather his cruelty that gives the stronger reason for doubting his sanity
Neither speaker expresses an opinion on this statement. Neither speaker addresses whether it’s more likely paranoia or cruelty explain Stalin’s sanity.
D
whether tyranny tends to lead to cruelty
Neither speaker expresses an opinion on this statement. Only the critic addresses tyranny, and the critic does not conclude that tyranny usually leads to cruelty.
E
whether it was Stalin’s psychological state or rather his political condition that was the primary cause of his cruel misdeeds
The critic and the writers disagree on this statement. The writers agree that Stalin’s psychological state explain his cruel misdeeds, while the critic would agree that Stalin’s political status explain his cruel misdeeds.