Summarize Argument: Causal Explanation
Scientists are super confused about penicillin-resistant bacteria in patients who don’t use penicillin. (Their confusion implies that resistance normally only occurs when people use penicillin.) However, the scientists have a solution: the bacteria are being naturally selected by mercury instead. This is supported by the bacteria being immune to mercury poisoning. We also learn that mercury-resistance genes are related to penicillin-resistance genes. Finally, the patients in question have mercury in their cavity fillings, giving us a source of mercury exposure.
Identify Argument Part
The assumption that some patients who take penicillin develop bacteria with an immunity to penicillin is part of what makes penicillin resistance without exposure to penicillin confusing.
A
It is a hypothesis that is taken by the scientists to be conclusively proven by the findings described in the passage.
Nothing in the argument is taken to prove a hypothesis that penicillin use can lead to penicillin-resistant bacteria. It’s also not a hypothesis at all, it’s an assumption that’s taken for granted and treated as a fact.
B
It is a generalization that, if true, rules out the possibility that some people who do not take penicillin develop bacteria resistant to it.
The scientists do not believe that penicillin leading to resistance would mean that penicillin is the only way to create resistance. The entire argument is based on the belief that some other factor could lead to resistance, and the scientists just have to figure out what.
C
It is a point that, in conjunction with the fact that some patients who do not take penicillin develop penicillin-resistant bacteria, generates the problem that prompted the research described in the passage.
This is exactly what the assumption about penicillin causing resistance does in the argument. It’s the reason that resistance in the absence of penicillin is confusing, leading to the scientists doing this research in the first place.
D
It is the tentative conclusion of previous research that appears to be falsified by the scientists’ discovery of the mechanism by which bacteria become resistant to mercury poisoning.
Nothing in this argument falsifies anything else. Mercury causing penicillin resistance doesn’t mean that penicillin can’t also cause penicillin resistance. Both are treated as compatible.
E
It is a generalization assumed by the scientists to conclusively prove that the explanation of their problem case must involve reference to the genetic makeup of the penicillin-resistant bacteria.
This is a trap; complicated does not mean correct. The assumption that penicillin can cause resistance doesn’t prove anything. It’s context for why the scientists are confused to start with.
Summary
Clothes made from natural fibers, unlike artificial fibers, often shrink when washed at high temperatures. Why? Because natural fibers are tightly curled in their original state. The manufacture of cloth requires straight fibers, so natural fibers are straightened before being made into cloth. High temperatures cause all fibers to return to their original states.
Strongly Supported Conclusions
In their original state, artificial fibers are straight.
A
Washing clothes made from natural fibers at low temperatures causes the fibers to straighten slightly.
This answer is unsupported. We don’t know from the stimulus what effect washing clothes at low temperatures causes. We only know that high temperatures cause natural fibers to shrink.
B
High temperatures have no effect on the straightness of fibers in clothes made from a blend of natural and artificial fibers.
This answer is unsupported. We don’t know from the stimulus what happens when clothes are made from a blend of fibers.
C
Clothes made from natural fibers stretch more easily than do clothes made from artificial fibers.
This answer is unsupported. We don’t know anything about stretching ability of either type of fiber from the stimulus.
D
If natural fibers that have been straightened and used for cloth are curled up again by high temperatures, they cannot be straightened again.
This answer is unsupported. We don’t know from the stimulus whether or not the process used to straighten the fibers originally could be used again once the fibers return to their original state.
E
Artificial fibers are straight in their original state.
This answer is strongly supported. We know from the stimulus that artificial fibers do not shrink when washed at high temperatures. We also know that high temperatures cause all fibers to return to their original state. Therefore, artificial fibers are originally straight.
Summarize Argument
The author concludes that there are no universal truths and the world is full of irregular events. She supports this by saying that the postmodern view rejects ideas of order and universal truth, emphasizing instead a belief in chaos and irregularity.
Identify and Describe Flaw
This is the cookie-cutter “fact vs. belief” flaw, where the author incorrectly assumes that because a large group of people believe something to be true, it must be a factual reality. In short, she essentially claims, “Postmodernists believe X. Therefore, X is true.”
On top of this, the author subtly contradicts herself. By claiming that there are no universal truths, the author attempts to make a universally true claim.
A
infers that something is the case because it is believed to be the case
The author infers that the postmodern view is factually the case, simply because it is believed to be the case. But other people’s belief in the view is not evidence that it is actually correct or true.
B
uses the term “universal” ambiguously
This is the cookie-cutter flaw of “equivocation,” where the author uses one term to mean multiple different things. But the other uses “universal” consistently, and (B) doesn’t describe the flaw in her argument.
C
relies on the use of emotional terms to bolster its conclusion
The author mistakes belief for fact, but she isn’t relying on emotional terms to strengthen her conclusion or manipulate her audience.
D
uses the term “order” ambiguously
This is the cookie-cutter flaw of “equivocation,” where the author uses one term to mean multiple different things. But the other uses “order” consistently, and (D) doesn’t describe the flaw in her argument.
E
fails to cite examples of modern theories that purport to embody universal truths
It’s true that the author doesn’t provide examples of modern theories, but this doesn’t weaken her argument, so it can’t be the flaw. Her conclusion is about the postmodern view; she only refers to the modern view contextually.
Summarize Argument
The author concludes gasohol should get more use. Why? Because plants can remove the amount of carbon dioxide gasohol produces, gasohol has a higher octane rating than gasoline, and burning gasohol emits less carbon monoxide than burning gasoline.
Notable Assumptions
The author assumes that gasohol and gasoline would be used for the same purpose, and that there’s no advantage to using gasoline over gasohol that outweighs the apparent benefits of gasohol.
A
Cars run less well on gasoline than they do on gasohol.
This strengthens the argument by ruling out a potential weakness of gasohol. It’s another reason to favor gasohol over straight gasoline.
B
Since less gasoline is needed with the use of gasohol, an energy shortage is less likely.
This strengthens the argument by providing another advantage to gasohol: it would save on gasoline usage, reducing the risk of an energy shortage.
C
Cars burn on the average slightly more gasohol per kilometer than they do gasoline.
This is a disadvantage to using gasohol, not an advantage. It implies drivers will have to refill their vehicles more often if gasohol is used widely.
D
Gasohol is cheaper to produce and hence costs less at the pump than gasoline.
This strengthens the argument by ruling out a potential weakness. It eliminates the possibility that gasohol is more expensive than gasoline.
E
Burning gasoline adds more carbon dioxide to the atmosphere than plants can remove.
This strengthens the argument by implying gasohol—which adds less carbon dioxide to the atmosphere than plants can remove—produces less carbon dioxide than gasoline. It’s an advantage to making the switch.