Pratt: Almost all cases of rabies in humans come from being bitten by a rabid animal, and bats do carry rabies. But there is little justification for health warnings that urge the removal of any bats residing in buildings where people work or live. Bats are shy animals that rarely bite, and the overwhelming majority of bats do not have rabies.

Summarize Argument
The author concludes that there’s not much justification for health warnings that urge removal of all bats that live in buildings where people work/live. This is based on the fact that bats are shy animals that rarely bite, and the fact that the overwhelming majority of bats don’t have rabies.

Notable Assumptions
The author assumes that the risk of being bitten by bats, whether they have rabies or not, does not provide significant justification for removing bats from all buildings where people work/live. The author assumes that there aren’t significant reasons we should remove all bats from the buildings, despite the unlikelihood of being bitten by a rabid bat.

A
A rabid bat is much more likely to infect another bat than to infect any other type of animal.
This suggests bats pose more risk to other bats than to other animals, such as humans. This is consistent with the author’s position, which is that we don’t have much justification to remove all bats from buildings with people.
B
Rabid bats are less mobile than other bats but are much more aggressive.
(B) gives us reason to think that rabid bats are likely to bite more often than other bats, which means that the general tendency (”rarely bite”) pointed out by the author does not apply to rabid bats. This undermines the support provided by that premise.
C
Most animals that carry rabies are animals of species that, under normal conditions, very rarely bite people.
This has no clear impact. Most animals with rabies could be raccoons, weasels, rats, etc. This doesn’t suggest that rabid bats are more likely to bite people than normal bats, or that there’s something about bats that should justify removing them from buildings.
D
The bat species with the highest incidence of rabies do not live in buildings.
If anything, this might support the author’s position by eliminating the possibility that the most rabid bats live in buildings, which might otherwise give us a reason to remove bats from buildings.
E
People are more likely to be aware of having been bitten by a bat if they were bitten by the bat inside a building.
This has no clear impact. If people are more likely to be aware of being bitten by a bat in a building, that doesn’t suggest we might want to remove bats from buildings.

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Psychologist: Thinking can occur without language. Researchers have demonstrated that three-month-old infants, who obviously have no knowledge of language, can detect anomalies in pictures—in a picture displaying a human face with three eyes, for example. The infants probably compare this picture with an internal representation of a typical human face. Thus, a thought of a typical human face must exist in the infants’ minds.

Summarize Argument
The Psychologist concludes that thinking can occur without language. Why? Because infants with no knowledge of language can spot irregularities in pictures. To do this, the infants probably compare the picture with an internal representation of what is typical, and so a thought of what is typical must exist in the infants’ minds.

Identify Argument Part
The statement in the last sentence is a sub-conclusion used to support the Psychologist’s main conclusion.

A
It is a conclusion drawn and used in turn as a premise to support a more general conclusion.
The statement is a sub-conclusion used as support for the Psychologist’s general conclusion: thinking can occur without language.
B
It is attributed to certain researchers as the main conclusion of their reasoning.
The statement is not the Psychologist’s main conclusion.
C
It is the main point of the psychologist’s argument.
The statement is not the Psychologist’s main conclusion.
D
It is used to refute the claim that infants have no knowledge of language.
The claim that infants have no knowledge of language is never refuted.
E
It states the hypothesis to be explained by the psychologist’s argument.
The statement is not a hypothesis.

2 comments

When a bird flies, powerful forces converge on its shoulder joints. The bird’s wings must be kept stable during flight, which cannot happen unless something balances these forces. The only structure in birds capable of balancing them is a ligament that connects the wing to the shoulder joint. So that ligament must be _______.

Summary
Any time a bird flies, powerful forces converge on its shoulder joints. If they are flying, the bird’s wings must be kept stable during flight. If their wings are stable, something needs to balance these powerful forces. The only structure in birds that can balance these forces is a ligament that connects the wings to the shoulder joint. So that ligament must be (the correct answer is the conclusion).

Strongly Supported Conclusions
The ligament is how birds stabilize their wings while flying.
Bird Flying -> wings stable -> balance powerful forces

A
the only structure that is indispensable to bird flight
The stimulus gives no indication that this ligament is the *only* structure necessary for bird flight. This is too strong to support and does not follow logically from the argument.
B
the reason that a bird’s wings must be kept stable during flight
The stimulus does not explain exactly *why* the bird’s wings must be kept stable. The stimulus is primarily concerned with the importance of stability, but not the reasons for it.
C
the sole connection between the wing and the shoulder joint
The stimulus says that the ligament is the only structure *capable of balancing* the wings, not that it is the sole connection. This is too strong to support.
D
the source of the powerful forces that converge on the shoulder joint
The stimulus does not explain where these powerful forces come from. The stimulus only says that these ligaments *balance* the powerful sources.
E
the means by which a bird stabilizes its wings during flight
The stimulus says that *the only structure* capable of balancing the wings is this ligament. Thus, the ligament must keep its wings stable because nothing else can.

5 comments