Summarize Argument
The columnist concludes that older studies claiming that nonstrenuous walking lowers one’s chances of developing cardio-respiratory illness should be ignored. As evidence, she cites a recent research report which found that only vigorous exercise has this result.
Identify and Describe Flaw
The columnist implicitly assumes that because the recent research report is newer, it must be more accurate than the older studies. However, she never actually provides any evidence for why the recent research is correct and the older studies are wrong.
A
fails to consider the possibility that the risk of developing certain cardio-respiratory illnesses can be reduced by means other than exercise
The columnist doesn’t fail to consider this possibility. She probably knows that other factors like diet or smoking affect one’s risk of cardio-respiratory illness, but she’s only discussing the effect of strenuous versus nonstrenuous exercise.
B
fails to consider that those who exercise vigorously are at increased risk of physical injury caused by exercise
The columnist is only arguing that vigorous exercise reduces one’s risk of cardio-respiratory illness. Whether it also increases one’s risk of physical injury is irrelevant.
C
overlooks the possibility that vigorous exercise may prevent life-endangering diseases that have little to do with the cardio-respiratory system
The columnist’s argument only addresses the effect of vigorous exercise on one’s risk of cardio-respiratory illnesses. Whether vigorous exercise also prevents other diseases is irrelevant.
D
fails to consider the possibility that those who engage in vigorous physical exercise are more likely than others to perceive themselves as healthy
The columnist is discussing the actual effect of vigorous exercise on one’s risk of cardio-respiratory illness. Whether people who exercise vigorously perceive themselves to be healthy has nothing to do with their actual health.
E
fails to show that a certain conclusion of the recent report is better justified than an opposing conclusion reached in older studies
The columnist assumes that the recent report is correct and the older studies are wrong, but she fails to provide any evidence for this. She doesn’t give any reason to believe that the conclusion of the recent report is better justified.
Summary
Traditional statistical methods predicted that some humans would live over 130 years.
EVT methods estimated the human lifespan limit to be between 113 and 124 years.
No human has lived beyond the EVT predicted limit.
EVT methods estimated the human lifespan limit to be between 113 and 124 years.
No human has lived beyond the EVT predicted limit.
Very Strongly Supported Conclusions
EVT estimates are more in line with the data on the longest living humans than are traditional statistical methods.
A
EVT is, in general, a more reliable method for projecting future trends based on past observations than are traditional statistical methods.
Unsupported. Like (E), the stimulus is only addressing each method’s analysis of data on human longevity. We can’t infer that EVT is a more reliable method in general for projecting any future trends.
B
EVT fits the data about the highest observed human life spans more closely than do traditional statistical methods.
Very strongly supported. EVT predicted a life span limit of 113-124 years, while traditional methods predicted a limit of over 130 years. Since the highest observed human life span is shorter than the EVT predicted limit, EVT fits the data more closely.
C
According to the findings derived through the use of EVT, it is physically impossible for any human being to live longer than 124 years.
Unsupported. Like (D), just because no one has lived longer than 124 years so far doesn’t mean that no one ever will. The EVT findings are just describing a statistically probable limit based on data; they aren’t implying that it’s physically impossible to live longer.
D
Given the results generated by EVT, there is no point in conducting research aimed at greatly extending the upper limit on human life spans.
Unsupported. Like (C), just because no one has lived longer than 124 years so far doesn’t mean that no one ever will or that researching longer lifespans is pointless.
E
Traditional statistical methods of empirical data analysis should eventually be replaced by some version of EVT.
Unsupported. Like (A), the stimulus is only addressing each method’s analysis of data on human longevity. We don’t have enough information about either method’s overall accuracy to infer that EVT should entirely replace traditional methods.
The number of different synthetic chemical compounds that are known to be carcinogenic but are nonetheless used as pesticides, preservatives, or food additives is tiny compared to the number of nonsynthetic carcinogenic compounds widely found in plants and animals. It is therefore absurd to suppose that the rise in the cancer rate in recent decades is due to synthetic carcinogens.
Summarize Argument
The author concludes that it’s absurd to blame synthetic carcinogens for rising cancer rates. She supports this by saying that the number of synthetic carcinogens used in preservatives and pesticides is very small compared to the number of nonsynthetic carcinogens found in plants and animals.
Identify and Describe Flaw
The author concludes that synthetic carcinogens are not responsible for rising cancer rates simply because there are fewer synthetic carcinogens than nonsynthetic ones. She overlooks the possibility that people’s exposure to synthetic carcinogens may be much more frequent or prolonged than their exposure to nonsynthetic carcinogens.
A
the rise in the cancer rate in recent decades is due to increased exposure to nonsynthetic pollutants
The author doesn’t overlook this possibility. Instead, she overlooks the possibility that the rise in cancer rates in recent decades is due to increased exposure to synthetic carcinogens.
B
the rise in the cancer rate in recent decades is due to something other than increased exposure to carcinogens
The author doesn’t overlook this possibility. She simply concludes that the rise in cancer rates is not caused by synthetic carcinogens; this allows for the possibility that it is caused by something other than exposure to carcinogens.
C
some synthetic chemical compounds that are not known to be carcinogenic are in other respects toxic
The author is only addressing synthetic chemical compounds that are known to be carcinogenic. Whether other synthetic compounds are toxic in other respects is irrelevant.
D
people undergo significantly less exposure to carcinogens that are not synthetic than to those that are synthetic
The author concludes that synthetic carcinogens aren’t responsible for rising cancer rates simply because there are more nonsynthetic carcinogens. She overlooks the possibility that people are exposed to synthetic carcinogens much more, even though there are fewer of them.
E
people can vary greatly in their susceptibility to cancers caused by nonsynthetic carcinogens
This may be true, but it doesn’t impact the author’s argument. She’s discussing the cause of rising cancer rates, not the susceptibility of certain people to cancers caused by certain carcinogens.
Summarize Argument: Counter-Position
The author refutes a claim made previously by some ecologists: The author argues that it is a mistake to think that natural selection will eventually result in organisms that are perfectly adapted to their environments. This is because perfect adaptation is impossible. It is impossible because environments vary a great deal, and no single set of characteristics could cause an organism to be adapted to all the conditions it might face.
Identify Conclusion
The conclusion is the author’s refutation of a once held claim: “It is a mistake to think, as ecologists once did, that natural selection will eventually result in organisms that will be perfectly adapted to their environments.”
A
It is not possible for an individual to be perfectly adapted to its environment.
This is a sub-conclusion, not the ultimate conclusion. The fact that perfect adaptation is impossible supports that natural selection will never result in perfect adaptation.
B
Natural selection will never result in individuals that will be perfectly adapted to their environments.
This accurately rephrases the conclusion. The author says it is a mistake to think that natural selection will ever result in perfect adaptation, which means natural selection will never result in perfect adaptation.
C
No single set of attributes could enable an individual organism to cope with all of the conditions that it might face.
This is a premise that supports the sub-conclusion that perfect adaptation is impossible.
D
Because an individual’s environment can vary tremendously, no individual can be perfectly adapted to its environment.
This encapsulates the sub-conclusion and its support. Both ultimately support the argument that natural selection will never result in perfect adaptation.
E
Ecologists once believed that natural selection would eventually result in individuals that will be perfectly adapted to their environments.
This is the position provided in the context that the argument refutes.
Summarize Argument: Counter-Position
The author concludes that trade routes between China and the West may have opened earlier than 200 B.C. To support this claim, the author highlights the benefits of the Silk Road as a trade route: level terrain, easily traversable mountain passes, and desert oases. The author claims that in addition to facilitating trade, these benefits would have also facilitated immigration from Africa and the Middle East to China. Since this migration began at least one million years ago, it is possible that the Silk road had opened earlier than 200 B.C.
Identify Argument Part
The claim in the question stem provides support for the possibility that the trade routes had opened before 200 B.C.
A
It is cited as conclusive evidence for the claim that trade links between China and the Middle East were established long before 200 B.C.
The author does not make a conclusive claim that the trade links were opened long before 200 B.C.; the author only claims that this was possible.
B
It is an intermediate conclusion made plausible by the description of the terrain along which the migration supposedly took place.
The claim in the question stem is not an intermediate conclusion; it is a premise that we accept at face value. The claim in the question stem does not gain support from any other part of the argument.
C
It is offered as evidence in support of the claim that trade routes between China and the West could easily have been established much earlier than is currently believed.
The claim in the question stem provides a reason to believe that trade routes could have opened earlier than 200 B.C.; it is a premise that supports the conclusion.
D
It is offered as evidence against the claim that trade routes between China and Africa preceded those eventually established between China and the Middle East.
There is no claim in the argument that trade routes between China and Africa preceded trade routes between China and the Middle East.
E
It is the main conclusion that the argument attempts to establish about intercourse between China and the West.
The main conclusion is the first sentence of the argument; the claim in the question stem is not the main conclusion.