Geographer: Because tropical storms require heat and moisture, they form especially over ocean surfaces of at least 26 degrees Celsius (79 degrees Fahrenheit), ocean temperatures that global warming would encourage. For this reason, many early discussions of global warming predicted that it would cause more frequent and intense tropical storms. But recent research shows that this prediction is unlikely to be borne out. Other factors, such as instabilities in wind flow, are likely to counteract global warming’s effects on tropical storm development.

Summarize Argument: Causal Explanation
Global warming is unlikely to cause more frequent and intense tropical storms. Early predictions suggested that global warming would increase the frequency and intensity of tropical storms by raising ocean temperatures conducive to such storms. However, this is unlikely because global warming will have other effects, such as changes in wind flow, that will counteract its impact on tropical storm development.

Identify Conclusion
The conclusion is the geographer’s opinion that early predictions about global warming’s impact on tropical storm development were wrong. The geographer concludes that global warming will probably not cause more frequent and intense tropical storms.

A
Tropical storms are especially likely to form over warm ocean surfaces.
This answer is incorrect because it summarizes the context of the stimulus. It explains why some predicted that global warming would lead to more frequent and intense tropical storms: tropical storms are more likely to form over warm oceans.
B
Contrary to early discussions, global warming is not the only factor affecting the frequency and intensity of tropical storms.
This misstates the conclusion. The correct conclusion is that global warming will probably not result in more frequent and intense storms. However, this answer claims that the conclusion is about global warming not being the only factor affecting storm frequency and intensity.
C
If global warming were reversed, tropical storms would be less frequent and less intense.
This isn’t an argument made in the stimulus. The geographer doesn’t consider what would be required to reverse global warming; she only disputes one prediction about the effects global warming may have. Since this claim isn’t made in the stimulus, it can’t be the main conclusion.
D
Instabilities in wind flow will negate the effect of global warming on the formation of tropical storms.
This addresses a premise, not the main conclusion. The geographer uses global warming's effect on wind flow to support her conclusion that global warming won't lead to more intense and frequent storms. Since this claim is supporting evidence, it can't be the main conclusion.
E
Global warming probably will not produce more frequent and intense tropical storms.
This accurately captures the main conclusion: the geographer believes that predictions about global warming’s effect on tropical storms were likely incorrect. The answer summarizes this by stating that global warming probably won't lead to more frequent and intense storms.

6 comments

Hospitals, universities, labor unions, and other institutions may well have public purposes and be quite successful at achieving them even though each of their individual staff members does what he or she does only for selfish reasons.

Summary

The individual staff members of hospitals, universities, labor unions, and other institutions do their work only for selfish reasons. However, the institutions themselves can still have public purposes and can achieve these public purposes successfully.

Strongly Supported Conclusions

Whether an institution can successfully achieve its public purpose may not depend on the intentions of that institution’s individual staff members.

An institution can possess a property that its members do not possess.

A
What is true of some social organizations is not necessarily true of all such organizations.

This is unsupported. The stimulus does not compare different kinds of social organizations; it only speaks to those institutions with public purposes.

B
An organization can have a property that not all of its members possess.

This is strongly supported. We are told that even though the staff members of an institution are selfishly motivated, the institution can have and achieve public purposes. Thus, the institution can have a property (pursuing public purposes) that not all of its members possess.

C
People often claim altruistic motives for actions that are in fact selfish.

This is unsupported. The stimulus does not tell us whether the staff members, who are selfish, claim to have altruistic motives. It merely tells us that the institution can have altruistic motives even though its members do not.

D
Many social institutions have social consequences unintended by those who founded them.

This is unsupported. The stimulus tells us nothing about the founders of these institutions or what their original intentions might have been. We only know that the institutions are currently able to have and achieve public purposes.

E
Often an instrument created for one purpose will be found to serve another purpose just as effectively.

This is unsupported. The stimulus does not refer to the creation or intended purpose of any instrument. We only know that an institution can have public purposes despite its selfish staff members.


11 comments

This video is for Passage A and Questions.


17 comments