Summarize Argument: Counter-Position
The author argues that mandatory minimum sentences for certain crimes are necessary in order to restrict judges’ discretion in deciding sentences. Why is restricting judicial discretion necessary? Because, says the author, people who rely on their judgment are often arbitrary and irrational, and there’s no reason to think judges are any different. So we can infer that judges are likely to use their discretion arbitrarily and irrationally, hence the need to restrict it.
Identify Conclusion
The conclusion is the author’s statement that restricting discretion “is precisely why mandatory minimum sentences are necessary.”
A
People believe that they have good judgment but never do.
Firstly, the use of “never” here makes this much stronger than what the author actually says. Secondly, even if this was stated, the author’s claim about people’s belief in their judgment is not supported by anything else, so not the conclusion.
B
Mandatory minimum sentences are too mechanical and reduce judicial discretion.
Like (C), the author argues against this statement. Some judges believe this, but the author’s argument is designed to prove the opposite, that mandatory minima are a necessary restriction.
C
Judges should be free to exercise their own judgment.
Like (B), the author argues against this statement. The point the argument is trying to make is that judges’ freedom of judgment should be limited because they may be arbitrary and irrational.
D
Judges are often arbitrary and irrational.
This can be inferred from the author’s argument, but the idea that judges are often arbitrary and irrational acts as support for the claim that restricting judges is necessary. That makes this an implicit sub-conclusion, not the main conclusion.
E
Mandatory minimum sentences are needed to help prevent judicial arbitrariness.
This is a good paraphrase of the author’s conclusion. The argument leads us to believe that judges would likely act arbitrarily without restriction, thereby supporting this conclusion, that mandatory minimum sentences are a necessary measure.
Summarize Argument
The environmentalists conclude gasoline should be replaced with methanol. Why? Because unlike gasoline, methanol doesn’t produce a significant amount of benzene when it’s burned.
Notable Assumptions
The environmentalists assume the advantages of switching from gasoline to methanol outweigh the disadvantages. In particular, they assume the formaldehyde produced by methanol is no more harmful than the benzene produced by gasoline.
A
The engines of some automobiles now on the road burn diesel fuel rather than gasoline.
This is irrelevant. The environmentalists don’t imply a switch is only worthwhile if it applies to all vehicles on the road.
B
Several large research efforts are under way to formulate cleaner-burning types of gasoline.
This is irrelevant. It doesn’t give any likelihood those efforts will be successful, nor does it say cleaner-burning gasoline would produce more or less benzene.
C
In some regions, the local economy is largely dependent on industries devoted to the production and distribution of automobile fuel.
This fails to distinguish between gasoline and methanol, both of which are discussed as automobile fuel. It doesn’t say a switch from gasoline to methanol would benefit these local economies.
D
Formaldehyde is a less potent carcinogen than benzene.
This supports the environmentalists’ proposal. It suggests burning methanol produces a less potent carcinogen than burning gasoline, which implies methanol may be safer than gasoline.
E
Since methanol is water soluble, methanol spills are more damaging to the environment than gasoline spills.
This weakens the environmentalists’ argument. It implies switching to methanol could backfire in the event of a spill, causing more damage to the environment than would gasoline.
"Surprising" Phenomenon
Prehistoric birds had growth rings suggesting they were cold-blooded animals, but dense blood vessels suggesting they were warm-blooded animals.
Objective
A hypothesis resolving this dispute must state a key similarity or difference between prehistoric birds and either cold-blooded or warm-blooded animals. It must allow for prehistoric birds to have both growth rings and dense blood vessels while being exclusively either cold-blooded or warm-blooded.
A
Some modern warm-blooded species other than birds have been shown to have descended from cold-blooded species.
This does not favor either possibility. Though other warm-blooded species descended from cold-blooded species, it is possible warm-blooded birds descended from warm-blooded prehistoric birds.
B
Having growth rings is not the only physical trait of cold-blooded species.
This is irrelevant information that does not favor either possibility. It is not stated whether prehistoric birds possessed any other traits of cold-blooded species.
C
Modern birds did not evolve from prehistoric species of birds.
In dispute is whether prehistoric birds were warm-blooded or cold-blooded, regardless of whether they were ancestors of modern birds. Both studies draw conclusions about prehistoric birds explicitly, so this does not favor either possibility.
D
Dense blood vessels are not found in all warm-blooded species.
This gets the desired relationship backward. It states that some warm-blooded species do not have dense blood vessels, but admits the possibility that all species with dense blood vessels are warm-blooded.
E
In some cold-blooded species the gene that is responsible for growth rings is also responsible for dense blood vessels.
This suggests prehistoric birds were cold-blooded. It implies that dense blood vessels are not necessarily evidence of warm-bloodedness, especially among animals with growth rings, calling into question the conclusion of the second study.