Official CR Solutions

CR29111.01 – The recycling of municipal solid waste

The recycling of municipal solid waste is widely seen as an environmentally preferable alternative to the prevailing practices of incineration and of dumping in landfills. Recycling is profitable, as the recycling programs already in operation demonstrate. A state legislator proposes that communities should therefore be required to adopt recycling and to reach the target of recycling 50 percent of all solid waste within 5 years.

CR67370.01 – Distressed by his own personal tragedies

Distressed by his own personal tragedies, the Roman philosopher Cicero once asked himself whether a wise person should try to achieve the Stoic ideal of complete emotionlessness. Cicero reasoned that, however desirable the goal may be, a wise person could never attain it, since emotions are not simply irrational urges. They are, rather, a product of one’s estimate of the goodness and badness of the events, people, and actions one witnesses.

CR61021.01 – Researchers in city X

Researchers in City X recently discovered low levels of several pharmaceutical drugs in public drinking water supplies. However, the researchers argued that the drugs in the water were not a significant public health hazard. They pointed out that the drug levels were so low that they could only be detected with the most recent technology, which suggested that the drugs may have already been present in the drinking water for decades, even though they have never had any discernible health effects.

CR51080.01 – Scientist: A greenhouse gas, for example, carbon dioxide, forms a transparent layer

Scientist: A greenhouse gas, for example, carbon dioxide, forms a transparent layer that traps solar heat beneath it in the earth’s atmosphere. Atmospheric levels of carbon dioxide are currently increasing, causing the climate to warm—an effect that is predicted by at least one computer model of the greenhouse effect. But the warming that has occurred is a great deal less than what would be expected based on the model. Therefore, _______.

CR66590.01 – Shirla: In figure skating competitions that allow amateur and professional skaters

Shirla: In figure skating competitions that allow amateur and professional skaters to compete against each other, the professionals are bound to have an unfair advantage. After all, most of them became professional only after success on the amateur circuit.

Ron: But that means that it’s been a long time since they’ve had to meet the more rigorous technical standards of the amateur circuit.

CR20521.01 – Errors in the performance of repetitive or “boring” tasks—often attributed

Errors in the performance of repetitive or “boring” tasks—often attributed to a momentary lapse in concentration—can be serious in such activities as flying a passenger aircraft. Is there any method that would provide warning of such lapses—for example by monitoring brain activity? Researchers scanned the brains of volunteers performing a repetitive task. When the tasks were being performed correctly, the volunteers’ brains showed activity in cognitive-processing regions. However, these regions became less active several seconds before some errors were made, and another brain region, region X, became active. The researchers concluded that the monitoring of region X could provide warning of an impending error.

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