Summarize Argument
The second group of doctors argue that bilirubin levels should be allowed to remain high in newborns. This is because the brain’s natural defenses prevent bilirubin from entering the brain.
Notable Assumptions
The second group of doctors assume the only reason to lower bilirubin levels in newborns would be to prevent bilirubin from entering the brain. This means they assume bilirubin is otherwise entirely neutral or even beneficial to newborns.
A
The treatment that most effectively reduces high levels of bilirubin in newborns has no known negative side effects.
These doctors are advocating for no treatment at all.
B
Some diseases that occur in newborns can weaken the brain’s natural defenses and allow bilirubin to enter.
This weakens the doctors’ argument. If bilirubin could in fact enter the brain, then bilirubin should be removed.
C
In newborns the pigment bilirubin, like other pigments, occurs not only in the blood but also in fluids involved in digestion.
The doctors are talking about removing bilirubin, generally. We don’t care if it’s in the blood or in digestive fluids.
D
Bilirubin neutralizes certain potentially damaging substances to which newborns are exposed at birth.
Bilirubin carries a distinct benefit for newborns. Thus, bilirubin levels shouldn’t be lowered in newborns.
E
Among doctors who recommend treating newborns to reduce high levels of bilirubin, there is general agreement about what levels should be considered excessively high.
We don’t care what these doctors think. We’re talking about the second group of doctors.
Summary
Two dates have been proposed as the approximate end point of the last ice age in North America:
First Date: Based on the presence of warmth-adapted open-ground beetles replacing cold-adapted arctic beetles in sediment samples.
Second Date: Based on the emergence of spruce forests as indicated by pollen grains found in the same sediment samples.
The first date (beetles) is over 500 years earlier than the second date (spruce forests).
First Date: Based on the presence of warmth-adapted open-ground beetles replacing cold-adapted arctic beetles in sediment samples.
Second Date: Based on the emergence of spruce forests as indicated by pollen grains found in the same sediment samples.
The first date (beetles) is over 500 years earlier than the second date (spruce forests).
Strongly Supported Conclusions
Warm adapted beetles appeared before the emergence of spruce forests.
A
Toward the end of the ice age, warmth-adapted open-ground beetles ceased to inhabit areas where the predominant tree cover consisted of spruce forests.
There is no information about what happened to warm-adapted beetles after the emergence of spruce forests. The forests emerged *after* the beetles
B
Among those sediments deposited toward the end of the ice age, those found to contain cold-adapted arctic beetle fragments can also be expected to contain spruce-pollen grains.
This is anti supported. The cold beetles came before the warm beetles, which in turn came before the spruce pollen grains. There is no support for them being together.
C
Ice masses continued to advance through North America for several hundred years after the end of the ice age.
The stimulus says nothing about whether ice masses advanced or not.
D
The species of cold-adapted arctic beetle that inhabited areas covered by ice masses died out toward the end of the last ice age.
The stimulus does not give information as to when the ice age *actually* ended (there are just two proposed dates). Thus, it is unreasonable to assume that the cold beetles died towards the end.
E
Toward the end of the ice age, warmth-adapted open-ground beetles colonized the new terrain opened to them faster than soil changes and seed dispersion established new spruce forests.
The stimulus says that the warm-adapted beetles replaced cold-adapted beetles 500 years before the emergence of spruce forests. Thus, it is supported that the beetles colonized the terrain faster than the establishment of the forests.
Essayist: Common sense, which is always progressing, is nothing but a collection of theories that have been tested over time and found useful. When alternative theories that prove even more useful are developed, they gradually take the place of theories already embodied in common sense. This causes common sense to progress, but, because it absorbs new theories slowly, it always contains some obsolete theories.
Summary
Common sense is always progressing.
Common sense is a collection of theories that have been tensed and found useful over time.
Alternative theories that are even more useful gradually replace the theories that are common sense.
This replacement happens slowly, so common sense always contains some obsolete theories.
Notable Valid Inferences
In common sense, there are always at least some theories that have more useful alternatives.
A
At least some new theories that have not yet been found to be more useful than any theory currently part of common sense will never be absorbed into the body of common sense.
This could be false. The stimulus discusses theories that are already developed and proven to be more useful. Further, the stimulus doesn’t discuss which theories will never be absorbed into common sense.
B
Of the useful theories within the body of common sense, the older ones are generally less useful than the newer ones.
This could be false. The stimulus does not give any relationship between age of theory and usefulness.
C
The frequency with which new theories are generated prevents their rapid absorption into the body of common sense.
This could be false. The stimulus just says that common sense absorbs new theories slowly; we don’t know the reason for this slow progress.
D
Each theory within the body of common sense is eventually replaced with a new theory that is more useful.
This could be false. We know that some theories are eventually replaced; we don’t know that each theory will be replaced.
E
At least some theories that have been tested over time and found useful are less useful than some other theories that have not been fully absorbed into the body of common sense.
This must be true. Progress is slow, so it takes time for alternative theories that have been proven to be more useful to be absorbed into common sense. Until these alternatives are absorbed into common sense, the theories in common sense are less useful than the alternatives.
Summary
The author concludes that we don’t have an obligation not to cut down trees. Why?
Because if an entity doesn’t have a corresponding right not to be cut down, then there is no obligation to that entity. And we know trees aren’t the kind of thing have have rights.
Because if an entity doesn’t have a corresponding right not to be cut down, then there is no obligation to that entity. And we know trees aren’t the kind of thing have have rights.
Notable Assumptions
We know from the premises that trees don’t have rights; so we don’t have any obligation toward trees not to cut them down. But does that prove we have no obligation at all not to cut down trees?
The flaw in the argument is that we might have an obligation to entities besides trees not to cut trees down. For example, maybe we’re obligated to our future children not to cut down trees.
The author must assume that we do not owe an obligation to other entities not to cut down trees.
A
If an entity has a right to certain treatment, we have an obligation to treat it that way.
Not necessary, because we already know that trees don’t have rights. So whatever must be true about things that do have rights doesn’t relate to the author’s reasoning.
B
Any entity that has rights also has obligations.
Not necessary, because we already know that trees don’t have rights. So whatever must be true about things that do have rights doesn’t relate to the author’s reasoning.
C
Only conscious entities are the sort of things that can have rights.
The concept of “conscious entities” has nothing to do with the reasoning of the argument. So (C) isn’t necessary.
D
Avoiding cutting down trees is not an obligation owed to some entity other than trees.
Necessary, because if it were not true — if avoiding cutting down trees IS an obligation owed to some entity other than trees — then we actually may still be obligated not to cut down trees, even if that obligation isn’t owed to the tree itself.
E
One does not always have the right to cut down the trees on one’s own property.
The argument concerns whether we have an obligation not to cut down trees. Whether we have a right to cut down trees is a separate issue.
Summary
In a humid climate, it’s difficult to grow cacti.
In a cold climate, it’s difficult to raise orange trees.
In most of a certain country, it’s easy to grow cacti or easy to raise orange trees.
In a cold climate, it’s difficult to raise orange trees.
In most of a certain country, it’s easy to grow cacti or easy to raise orange trees.
Notable Valid Inferences
In most of a certain country, it’s either not humid or not cold. We’re looking for what must be false, so the correct answer should contradict this inference.
A
Half of the country is both humid and cold.
Must be false. We can infer that in most (over half) of the country, it’s either not humid or not cold. If half of the country is both humid and cold, that makes it impossible for over half to be not humid or not cold.
B
Most of the country is hot.
Could be true. As long as most of the country is not humid, this is consistent with the stimulus.
C
Some parts of the country are neither cold nor humid.
Could be true. We know most of the country is not cold or not humid. It’s possible some parts are neither cold nor humid.
D
It is not possible to raise cacti in the country.
Could be true. As long as in most of the country it’s easy to raise orange trees, it could be that cacti can’t be raised in the country.
E
Most parts of the country are humid.
Could be true. As long as most of the country is not cold, it’s possible most of the country is humid.
Erich: Certainly not.
Leslie: Just as I expected! It is clear from your answer that your hands are more important to you than possessing the world. But your entire body is necessarily more important to you than your hands. Yet you are ruining your health and harming your body in your quest for a treasure that is much less valuable than the whole world. I rest my case.
Summarize Argument
Leslie tells Erich that his quest for treasure is irrational. She lays out her argument by demonstrating that Erich agrees that his hand is more valuable to him than possessing the world. She knows Erich’s body is more important to him than his hands, and that the treasure is less valuable than the whole world. However, Erich is harming his body by searching for treasure, which seems contrary to the assertion he agreed with. This makes his search irrational.
Identify Conclusion
The conclusion is what Leslie is trying to prove with her ‘case’: “your quest for the treasure is irrational.”
A
Erich would not sacrifice one of his hands in order to possess the world.
This is a statement that Leslie uses to prove that Erich’s quest is irrational.
B
Erich should not risk his physical well-being regardless of the possible gains that such risks might bring.
Leslie is not arguing “regardless of the gains.” She demonstrates that the gains would be less valuable to Erich than what he is losing.
C
Erich is irrationally risking something that is precious to him for something that is of no value.
Leslie does not claim that the treasure has “no value.” She instead shows he is losing something more valuable for something less valuable.
D
Erich can be convinced that his quest for the treasure is irrational.
Leslie is trying to convince Erich, but she is not claiming that he can be convinced. She employs her evidence to convince him, not to show that he is persuadable.
E
Erich is engaging in irrational behavior by pursuing his quest for the treasure.
This accurately rephrases Leslie’s conclusion. She structures her argument to show that Erich’s quest is irrational.