Summarize Argument: Phenomenon-Hypothesis
The author concludes that the melting of the ice contributed to the earthquakes in Sweden at the end of the last Ice Age. This is because melting ice reduced the weight pressing on the earth’s crust, which caused lasting cracks to form in the earth’s crust.
Notable Assumptions
The author assumes that cracks in the earth’s crust make earthquakes more likely to happen, or themselves constitute earthquakes. He also assumes that Sweden is situated in a location where the cracks caused by melting ice caused earthquakes.
A
The earth’s crust tends to crack whenever there is a sudden change in the pressures affecting it.
This more or less restates a premise. We need to strengthen the connection between the premises and the conclusion.
B
There are various areas in Northern Europe that show cracks in the earth’s crust.
The author never claims Sweden is the only place in Northern Europe where such earthquakes happened.
C
Evidence of severe earthquakes around the time of the end of the Ice Age can be found in parts of northern Canada.
While this strengthens the claim melting ice correlates with earthquakes, the author makes a causal claim. We want to strengthen the causation.
D
Severe earthquakes are generally caused by cracking of the earth’s crust near the earthquake site.
Cracks in the earth’s crust cause earthquakes. This strengthens the causal relationship that the author claims exists by clarifying how melting ice relates to earthquakes.
E
Asteroid impacts, which did occur at the end of the Ice Age, generally cause severe earthquakes.
This totally weakens the author’s argument. Asteroids, not melting ice, were responsible for the earthquakes.
Summary
A hummingbird’s egg accounts for 15 percent of an adult hummingbird’s weight. An adult goose is much larger than a hummingbird, but a goose’s egg accounts for only 4 percent of an adult goose’s weight. An adult ostrich is much larger than a goose, but ostrich eggs only account for 1.6 percent of an adult ostrich’s weight.
Strongly Supported Conclusions
The larger a bird species is, the smaller the ratio is between egg weight and the body weight of an adult bird.
A
The eggs of different bird species vary widely in their ratio of volume to weight.
This answer is unsupported. In the stimulus, we are comparing egg weight and volume to the weight and volume of an adult bird. This answer is comparing egg weight and volume of one species compared to the egg weight and volume of another.
B
The smaller and lighter the average adult members of a bird species are, the larger and heavier the eggs of that species are.
This answer is unsupported. From the stimulus, we only know that the ratio between the weight and volume of an egg increases the smaller the adult bird is. This doesn’t mean that the eggs are larger, just that they account for a bigger proportion of an adult’s weight.
C
The ratio of egg weight of a species to body weight of an adult member of that species is smaller for larger birds than for smaller ones.
This answer is strongly supported. This answer accurately captures the comparative difference of proportion between egg weight and volume of different bird species.
D
The size of birds’ eggs varies greatly from species to species but has little effect on the volume and weight of the adult bird.
This answer is unsupported. We don’t know from the stimulus anything about the size of any adult bird’s eggs. Rather, we only know something about the proportion of egg weight and volume compared to an adult bird.
E
Bird species vary more in egg size than they do in average body size and weight.
This answer is unsupported. We don’t know from the stimulus whether bird species vary in egg size at all. We only know that in different species of birds, egg weight and volume accounts for a different proportion of an adult bird’s weight.
Summarize Argument
The author concludes that it is unlikely that disease will be eradicated. As support for this conclusion, the author states that most diseases are caused by prolific microorganisms that respond to medicines by quickly evolving immunities while maintaining their ability to infect and kill humans. In other words, a byproduct of the use of medicines is the evolution of potentially harmful microorganisms.
Identify Argument Part
The claim in the question stem is the main conclusion of the argument.
A
It is a conclusion that is claimed to follow from the premise that microorganisms are too numerous for medicines to eliminate entirely.
While (A) correctly identifies the claim in the question stem as a conclusion, the conclusion does not follow from the premise that microorganisms are too numerous for medicines to eliminate them entirely. Rather, the problem is that microorganisms quickly evolve immunities.
B
It is a conclusion for which a description of the responses of microorganisms to the medicines designed to cure the diseases they cause is offered as support.
(B) correctly identifies the claim in the question stem as the conclusion, and shows the correct relationship between the conclusion and the support. It is the response of microorganisms to medicines––their ability to evolve immunities––that supports the conclusion.
C
It is a premise offered in support of the claim that most disease-causing microorganisms are able to evolve immunities to medicines while retaining their ability to infect humans.
The claim in the question stem is the conclusion, not a premise.
D
It is a generalization used to predict the response of microorganisms to the medicines humans use to kill them.
The claim in the question stem is the conclusion; it is not a generalization. Further, the claim in the question stem is a claim about the existence of disease in the world, not a prediction about how microorganisms respond to medicine.
E
It is a conclusion that is claimed to follow from the premise that most microorganisms are immune to medicines designed to kill them.
(E) does correctly identify the claim in the question stem as a conclusion. However, the problem with medicines isn’t that the microorganisms that they are designed to kill are immune to them; instead, the problem with medicines is that microorganisms respond by becoming immune.
Summarize Argument
The argument claims that Claudette is probably a classical pianist. This is because most classical pianists recognize Schumann's works, and Claudette happens to also recognize them. Further, most people who aren’t classical pianists would not have recognized them.
Identify and Describe Flaw
These two ‘most’ relationships only tell us how likely someone may be to recognize or not recognize Schumann’s works. They say nothing about how likely someone is to be a classical pianist. It’s entirely possible that most people who recognize her works aren’t classical pianists. The argument’s flaw lies in the mistaken assumption that, among everyone in the world who recognizes Schumann's works, most of them are classical pianists. This flaw amounts to the author interpreting a ‘most’ relationship in the wrong direction.
A
ignores the possibility that Claudette is more familiar with the works of other composers of music for piano
This is irrelevant. The argument claims that she’s probably a classical pianist because she recognizes Schumann’s works. This claim is unaffected by how many other works she does or doesn’t recognize.
B
presumes, without providing justification, that people who have not heard of Clara Schumann do not recognize her works
This is irrelevant. Whether these other people recognize Schumann or not has no bearing on whether Claudette is likely to be a classical pianist.
C
presumes, without providing justification, that classical pianists cannot also play other musical instruments
The argument doesn’t presume this, and even if it were to, it wouldn’t matter. Whether classical pianists play other instruments or not is irrelevant to whether Claudette is likely to be one.
D
relies for its plausibility on the vagueness of the term “classical”
The term “classical” is not vague since it consistently refers to a specific kind of pianist.
E
ignores the possibility that the majority of people who recognize many of Clara Schumann’s works are not classical pianists
This describes the fact that while most classical pianists may recognize Schumann’s works, many other kinds of people may recognize them as well. Claudette could easily be one of those other people who recognize the works without being a classical pianist.