Summarize Argument: Phenomenon-Hypothesis
Some naturalists hypothesize that polar bears can navigate from unfamiliar territory to familiar areas across long distances. As support for this hypothesis, they reference a polar bear that returned home after it was released over 500 km away.
Notable Assumptions
The stimulus defines navigation as finding a way from an unfamiliar territory to familiar areas, but in the example of the polar bear, we don’t know if the polar bear was released in unfamiliar territory. The naturalists assume that the polar bear was released in unfamiliar territory. They also assume that the polar bear didn’t receive any other assistance in making its way home.
A
The polar bear stopped and changed course several times as it moved toward its home territory.
The fact that the polar bear changed course several times doesn’t contradict the fact that the polar bear successfully made it home after being released 500 km away.
B
The site at which the polar bear was released was on the bear’s annual migration route.
(B) weakens the argument because it shows that the polar bear did not meet one of the requirements of navigation: finding its way through unfamiliar territory. If the site at which the polar bear was released was familiar, then its actions don’t fit the definition of navigation.
C
The route along which the polar bear traveled consisted primarily of snow and drifting ice.
The terrain through which an animal is navigating is not relevant to the argument; we only care about if the polar bear was navigating.
D
Polar bears are only one of many species of mammal whose members have been known to find their way home from considerable distances.
It doesn’t matter how many animals are capable of finding their way home across long distances. We only care about if the example cited by the naturalists is aligned with the definition of navigation.
E
Polar bears often rely on their extreme sensitivity to smell in order to scent out familiar territory.
The argument is concerned with whether or not the polar bear was navigating, not how it was able to do so. The fact that polar bears often use smell is not relevant.
Summary
If you have no keyboarding skills, then you will not be able to use a computer. If you are not able to use a computer, then you will not be able to use a word processing program to write your essays.
Notable Valid Inferences
If you are able to use a word processing program to write your essays, then you have keyboarding skills.
A
If you have some keyboarding skills, you will be able to write your essays using a word processing program.
Could be false. We don’t have any conditional statements in the stimulus to tell us what occurs when a person does have keyboarding skills. Our first conditional statement tells us what occurs when a person does not have keyboarding skills.
B
If you are not able to write your essays using a word processing program, you have no keyboarding skills.
Could be false. We don’t have any conditional statements in the stimulus to tell us what occurs when a person is not able to use a word processing program. Not being able to use a word processing program is a necessary condition, it is not a sufficient condition.
C
If you are able to write your essays using a word processing program, you have at least some keyboarding skills.
Must be true. As shown below, this answer choice is the correct contrapositive of our conditional chain. 
D
If you are able to use a computer, you will probably be able to write your essays using a word processing program.
Could be false. The only statement we could infer if a person can use a computer is that that person has keyboarding skills. This answer choice is an incorrect contrapositive.
E
If you are not able to write your essays using a word processing program, you are not able to use a computer.
Could be false. We don’t have any conditional statements in the stimulus to tell us what occurs when a person is not able to use a word processing program. Not being able to use a word processing program is a necessary condition, it is not a sufficient condition.
Smith: Granted, children’s interests are not always the same as their parents’; governmental deficits incurred by their parents’ generation will later affect their own generation’s standard of living. But even if children are told about the issues affecting them, which is not generally the case, their conceptions of what can or should be done are too simple, and their time horizons are radically different from those of adults, so we cannot give them the responsibility of voting.
Summarize Argument
Rossi claims that children should have the right to vote. To support this conclusion, Rossi states a principle that it is undemocratic for anyone to live under a government that doesn’t represent their interests. According to Rossi, children’s interests can differ from their parents’ interests—presumably making it undemocratic to ban children from voting.
Describe Method of Reasoning
Rossi’s argument starts with the general principle that it’s undemocratic not to represent citizens’ interests. Rossi then points out a particular case where that principle is violated: children’s interests aren’t always represented by their parents. Based on this, Rossi concludes that we should change our system so the principle is respected, by allowing children to vote.
A
It makes an appeal to a general principle.
Rossi appeals to the general principle that it’s undemocratic for a government not to represent the interests of all those living under it. The apparent violation of this principle leads to Rossi’s conclusion that children should get to vote.
B
It denies the good faith of an opponent.
Rossi doesn’t mention any opponents, and isn’t directly responding to another argument. There’s no issue of good faith here.
C
It relies on evaluating the predictable consequences of a proposal.
Rossi doesn’t address any predictable consequences of the proposal to allow children to vote (or of any other proposal).
D
It substitutes description for giving a rationale for a policy.
Rossi does give a rational for the proposed policy of allowing children to vote: that it would make society more democratic.
E
It employs a term on two different occasions in different senses.
There’s no term that Rossi uses to mean two different things on two different occasions. All the terms in Rossi’s argument appear to mean the same thing every time they’re used.