Business writer: Although the demand for Corinne wristwatches currently far outstrips supply, it would be a mistake for the manufacturer to increase supply to meet demand. The current demand results from the public’s perception that the wristwatches are in short supply, and the wristwatches are in short supply merely because they are produced in very limited quantities. The excess demand creates the impression that the wristwatches are greatly desired, and that impression in turn helps account for consumers’ desire for them. If the supply of Corinne wristwatches were to increase to meet demand, excess demand for them would be eliminated, with the result that the wristwatches would no longer be desired.

Summarize Argument: Counter-Position
The business writer concludes that it would be a mistake for the manufacturer of Corrine wristwatches to increase the supply to meet demand for the following reasons:
1. The current high demand is due to the public’s perception that the watches are in short supply.
2. This is because they are produced in very small quantities.
3. The scarcity of these watches drives desire.
4. If the supply were increased, the perceived scarcity of the watches would diminish
5. This would decrease the demand for the watches.

Identify Argument Part
This is the conclusion of the argument. The following sentences explain the reasoning to support this claim.

A
an introductory claim that describes the position to be refuted by the argument
The claim is not refuted by the argument. It is the main conclusion that is supported by everything else that follows.
B
a justification of the relevance of the evidence cited
The claim is not used to justify the relevance of the evidence. The evidence (premises) a are used to support this claim.
C
a premise of the argument
The claim is not a premise. It is not used to support anything. It only receives support.
D
an opinion offered in support of one of the argument’s premises
The claim does not support a premise; it does not support anything, as it is the main conclusion of the argument.
E
the conclusion toward which the argument is directed
This is an accurate description of the claim. The entire argument supports the conclusion by explaining why increasing the supply of watches would be a mistake.

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Body temperature can be estimated by the relative proportion of two oxygen isotopes in bone. Such estimates derived from dinosaur fossils suggest that dinosaurs had nearly the same body temperature in their limbs as in the rest of their bodies. Typically, the core body temperature of cold-blooded animals today is much higher than the body temperature in their limbs. Thus, dinosaurs were probably warm-blooded.

Summarize Argument
Dinosaurs were likely warm-blooded because the oxygen isotopes in their bones suggest that their limbs had the same body temperature as the rest of their body. And typically, the body temperature of modern cold-blooded animals much is higher than their limbs.

Notable Assumptions
The author assumes that the discrepancy in the body/limb temperature of modern cold-blooded animals was the same as cold-blooded animals during the time of the dinosaurs. The author also assumes that the process of determining body temperature from bones is applicable to dinosaur fossils.

A
Large warm-blooded animals keep their core body temperature slightly higher than the body temperature in their limbs.
This does not weaken because dinosaurs' core body and limb temperature are still much closer to the ratio of warm-blooded animals. Thus, this does not weaken the claim that dinosaurs were warm-blooded.
B
The fossilization process introduces changes to bones such that their original oxygen isotope ratios cannot be predicted.
This weakens the argument because it casts doubt on the process by which the evidence was discovered. If the fossilization process changes the oxygen distribution, then the evidence about the body temperature cannot be relied on to reach a sound conclusion.
C
Oxygen was more abundant in Earth’s atmosphere during the period in which the dinosaurs lived.
You must make several unwarranted assumptions to make this work. The fact that more oxygen was prevalent in the atmosphere does not mean dinosaur bones have more oxygen. AC B does a much better job of weakening the process of how the evidence was collected.
D
Small warm-blooded animals like mice tend to have more uniform body temperatures than do large warm-blooded animals like elephants.
This does not weaken the argument that dinosaurs are warm-blooded. This AC just compares small and large warm-blooded animals. You have to make many unwarranted assumptions for this to work.
E
Warm-blooded animals are more active and use more oxygen than cold-blooded animals.
This is irrelevant to the argument’s reasoning. This just provides a characteristic of warm-blooded animals but does not challenge the evidence or reasoning in the stimulus.

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A recent study found that small rats were approximately twice as likely, and large rats only half as likely, to suffer from heart problems than were rats of average size.

"Surprising" Phenomenon
Why are small rats more likely than normal rats to suffer from heart problems, and large rats are less likely than normal to suffer form heart problems?

Objective
This is an EXCEPT question. The four wrong answers will help differentiate small rats from other rats in a way that makes them more likely to have heart problems, or it will help differentiate large rats from other rats in a way that makes them less likely to have heart problems.

A
Small rats are more likely than large rats to suffer from fatal diseases that tend to strike earlier than do heart problems.
This deepens our confusion. If small rats are more likely than large rats to die before getting heart problems, then we’d expect the overall rate of heart problems among small rats to be lower than for the other rats, who are more likely to survive to the age of getting heart problems.
B
Small rats generally have smaller blood vessels than do large rats, vessels that can more easily be clogged with fatty deposits.
If small rats have smaller blood vessels, which can be more easily clogged with fat, that’s a potential causal mechanism that could explain the smaller rats’ increased risk of heart problems.
C
The larger a rat is, the more successful it will be at defending itself, and therefore the less stressful its existence will be.
The smaller ones have more stress, which might lead to increased heart problems. The larger rats have less stress, which might lead to fewer heart problems. And the average rats are in the middle for stress, which might lead to being in the middle for heart problems.
D
In addition to being the leading cause of weak hearts in adult rats, malnutrition at early stages of development causes rats to be undersized.
This tells us malnutrition causes both a weak heart and smaller body size. This could explain why the smaller rats have more heart problems: those rats were more likely to be the malnourished ones.
E
Although large rats are no more active than rats of average size, they tend to be much more active than small rats, resulting in greater cardiovascular conditioning.
(E) establishes that small rats have less cardiovascular conditioning (meaning conditioning related to the heart) than the average and large rats. This helps explain why small rats have more heart problems than the other groups.

3 comments

Medical researcher: Studies in North America have shown that the incidence of heart disease in a population is closely related to the average fat consumption for individuals in that population. However, although residents of France consume, on average, as much fat as residents of North America, heart disease presently occurs half as frequently among the French as among North Americans.

"Surprising" Phenomenon

Why do residents of France have a rate of heart disease half that of North Americans, even though they eat as much fat as North Americans, and studies in North America show that the rate of heart disease in a population is closely related to the average fat consumption of individuals in that population?

Objective

The correct answer should tell us something special about the French compared to North Americans that would lead to a lower rate of heart disease.

A
The average level of fat consumption by the French has been falling for several decades.

This doesn’t differentiate the French from North Americans. In addition, we already know the French eat just as much fat as North Americans. We have no reason to think that higher rates of fat consumption in the past have any impact.

B
Other factors of diet besides high consumption of fat have not been similarly linked with incidence of heart disease.

If this has any impact, it deepens our confusion. If other diet factors haven’t been linked to heart disease, then it’s harder to explain the discrepancy by pointing to a difference in other foods eaten by the French and North Americans.

C
Heart disease takes years to develop and the average level of fat consumption in France increased to North American levels only a few years ago.

This points out a difference between French and North Americans that could explain the French people’s lower heart rate. They only recently reached the same level of fat consumption as North Americans, so the French’s heart disease rate may not have had enough time to rise.

D
Certain diseases other than heart disease have also been linked to average fat consumption, and the French have a higher incidence of these than do North Americans.

We’re trying to explain the discrepancy in heart disease rate. Lack of difference in rates of other disease doesn’t help explain why the French have a different rate of heart disease from North Americans.

E
Cigarette smoking significantly increases the risk of heart disease and France has a higher percentage of cigarette smokers in its population than does North America.

This deepens our confusion, because it would lead us to expect the French to have a higher rate of heart disease than North Americans. But they actually have a lower rate.


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