Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that air pollution most likely eradicated the plant diseases black spot and tar spot. This is based on the observation that those two diseases disappeared in industrial English cities during the Industrial Revolution—places where there was high air pollution.
Notable Assumptions
The author assumes that the observed correlation between air pollution in English cities and the disappearance of the two plant diseases is due to the former causing the latter. This means that the author also assumes there was no alternative cause of the diseases’ disappearance.
A
Scientists theorize that some plants can develop a resistance to air pollution.
Like (C), this is irrelevant because we don’t care about plants’ reaction to pollution, only two specific plant diseases.
B
Certain measures help prevent infection by black spot and tar spot, but once infection occurs, it is very difficult to eliminate.
This is too vague to be useful, because it doesn’t tell us why these diseases are difficult to eliminate or what might succeed in eliminating them.
C
For many plant species, scientists have not determined the effects of air pollution.
Like (A), this is irrelevant because the author’s hypothesis is about plant diseases, not plants themselves. How plants are affected by air pollution is totally outside the argument’s domain.
D
Black spot and tar spot returned when the air in the cities became less polluted.
This strengthens the author’s argument by reinforcing the relationship between air pollution and the two plant diseases. If the diseases come back when pollution decreases, that backs up the hypothesis of a causal relationship.
E
Black spot and tar spot were the only plant diseases that disappeared in any English cities during the Industrial Revolution.
This is irrelevant, because we’re only concerned with these two diseases, and this tell us nothing new about them. We simply don’t care about what happened to other plant diseases.
Summary
There are many advantages that allow cable TV stations to attract more advertisers than broadcast networks. They can target specific audiences with 24-hour news, sports, or movies, while broadcast networks need to provide a mix of programs. They can also charge lower advertising rates since they receive money from subscriber fees. Also, many cable channels have expanded globally with international programming.
Strongly Supported Conclusions
Broadcast networks aren’t subsidized by viewers through subscriber fees.
Some advertisers prefer to run their ads on stations with viewers who watch 24-hour news, sports, or movies.
Some advertisers prefer to run their ads on a station with lower advertising rates.
Some advertisers prefer to run their ads on a station that has expanded worldwide.
Note: We’re seeking the answer choice that is not supported.
Some advertisers prefer to run their ads on stations with viewers who watch 24-hour news, sports, or movies.
Some advertisers prefer to run their ads on a station with lower advertising rates.
Some advertisers prefer to run their ads on a station that has expanded worldwide.
Note: We’re seeking the answer choice that is not supported.
A
Some broadcast networks can be viewed in several countries.
Unsupported. The stimulus tells us that many cable stations have expanded worldwide and that this is an advantage that they have over broadcast networks. It does not discuss whether any broadcast networks can be viewed in several countries.
B
Broadcast networks do not rely on subscriber fees from viewers.
Strongly supported. Cable stations receive money from subscriber fees and this is an advantage that they have over broadcast networks. We can conclude then that broadcast networks do not rely on subscriber fees from viewers.
C
Low costs are often an important factor for advertisers in selecting a station or network on which to run a TV ad.
Strongly supported. Cable stations can attract many more advertisers than broadcast networks in part because they can charge lower advertising rates. We can thus conclude that advertising rates are important to advertisers who are deciding which network to run an ad on.
D
Some advertisers prefer to have the opportunity to address a worldwide audience.
Strongly supported. We are told that worldwide expansion is an one advantage that allows cable stations to attract more advertisers than broadcast networks. Thus, we can conclude that some advertisers prefer to have the opportunity to address a worldwide audience.
E
The audiences that some advertisers prefer to target watch 24-hour news stations.
Strongly supported. Cable stations can target audiences with 24-hour news, while broadcast networks cannot. This is advantageous to cable stations in attracting advertisers. Thus, some advertisers must prefer to target audiences that watch 24-hour news stations.
Mytheco executive: But many of the technical writers have worked for Mytheco longer than have many of the programmers. Since salary and benefits at Mytheco are directly tied to seniority, the 20 percent pay difference you mention is perfectly acceptable.
Summarize Argument
The executive concludes that the pay difference between programmers and technical writers at Mytheco is acceptable. This is because pay is tied to seniority, and many technical writers have worked at Mytheco longer than many programmers.
Notable Assumptions
The executive assumes that “many” technical writers having greater seniority than “many” programmers means that the average technical writer has greater seniority than the average programmer.
A
whether any of the technical writers at Mytheco once worked as programmers at the company
Irrelevant. We don’t care if some programmers became technical writers. We care if the pay difference is in fact tied to seniority.
B
how the average seniority of programmers compares with the average seniority of technical writers
If the average technical writer has seniority resulting in 20% more pay than the average programmer, the executive’s argument is strengthened. If the average technical writer has seniority resulting in less than 20% more pay, something else must explain the pay difference.
C
whether the sorts of benefits an employee of Mytheco receives are tied to the salary of that employee
We don’t care about the sorts of benefits. We care about pay difference, which we have no reason to believe is tied to the sorts of benefits employees receive.
D
whether the Mytheco executive was at one time a technical writer employed by Mytheco
How would this affect the executive’s argument? This doesn’t point to any meaningful difference or similarity between technical writers and programmers, which is what we need to evaluate the executive’s argument.
E
how the Mytheco executive’s salary compares with that of the programmers
We’re not comparing between executives and programmers. We’re comparing between programmers and technical writers.
Summary
Male Trinidadian guppies with large spots are more attractive to females than males with small spots, who have fewer chances to mate. However, small-spotted guppies are better at avoiding predators, so in areas with many predators, only the small-spotted ones survive to maturity.
Strongly Supported Conclusions
A trait that helps an organism in one situation (such as mating) might harm it in a different situation.
Some seemingly advantageous traits may ultimately have negative consequences in certain environments.
Some seemingly advantageous traits may ultimately have negative consequences in certain environments.
A
A trait that helps attract mates is sometimes more dangerous to one sex than to another.
Unsupported. The stimulus discusses the effects of spot size among male guppies, but does not discuss spot size among female guppies. So we do not know whether this trait is more dangerous to one sex than to another.
B
Those organisms that are most attractive to the opposite sex have the greatest number of offspring.
Unsupported. Large-spotted guppies are more attractive to females and thus have more frequent mating opportunities, but they are less likely to live to maturity in waters with many predators. We do not know whether they have the greatest number of offspring.
C
Those organisms that survive the longest have the greatest number of offspring.
Unsupported. Small-spotted guppies are more likely to live to maturity in waters with many predators, but they are also less attractive to females and thus have less frequent mating opportunities. We do not know which kind of guppy has the greatest number of offspring.
D
Whether a trait is harmful to the organisms of a species can depend on which sex possesses it.
Unsupported. Like answer choice A, the stimulus does not discuss spot size among female guppies. So we do not know whether this trait is more harmful to one sex than to another.
E
A trait that is helpful to procreation can also hinder it in certain environments.
Strongly supported. The stimulus closely conforms to this generalization because it shows that large spots among guppies are helpful in mating but harmful in waters with many predators.