Environmentalist: Snowmobiles in the park north of Milville create unacceptable levels of air pollution and should be banned.

Milville Business Spokesperson: Snowmobiling brings many out-of-towners to Milville in the winter months, to the great direct financial benefit of many local residents. In addition, the money the town collects in fees for the recreational use of the park indirectly benefits all Milville residents. So, it is basic economics for us to put up with the pollution.

Which of the following, if true, could best be used by the environmentalist to counter the business spokesperson's argument?

In many scientific disciplines, scientists generally do not do highly creative work beyond the age of forty, a tendency that has normally been taken to show that aging carries with it a loss of creative capacity. However, by the age of forty most scientists have been working in their chosen field for at least fifteen years, so an alternative explanation is that spending too long in a single field reduces the opportunity for creative thought.

Investigating which of the following would be most useful in choosing between the competing explanations described above?

In Europe, many large animal species, such as mammoths, became extinct soon after humans first migrated to the animals' areas of habitation. The spread of such extinctions closely followed the pattern of human migration. However, since humans tended to migrate to areas as the climate in those areas began to warm, the extinctions might have been precipitated by the climatic warming rather than by human migration.

Which of the following, if true, provides the best evidence that it was human migration and not climatic change that precipitated the extinctions?

To improve the long-term savings rate of the citizens of Levaska, the country's legislature decided to implement a plan that allows investors to save up to $1,000 per year in special accounts without paying taxes on the interest earned unless withdrawals are made before the investor reaches age sixty-five. Withdrawals from these accounts prior to age sixty-five would result in the investor's having to pay taxes on all the accumulated interest at the time of withdrawal.

Which of the following, if true, most strongly supports the prediction that the legislature's plan will have its intended effect?

Which of the following most logically completes the argument below?

Twenty percent of the stores in Morganville's downtown shopping district will fail within five years because they will be competing directly with the SaveMart discount department store newly opened in East Morganville. The downtown shopping district has lost business at this rate before and has always completely rebounded. Confidence that it will rebound again from the losses it is now about to suffer is ill founded, however, because __________.

Which of the following most logically completes the argument?

According to experts on shopping behavior, more shoppers would shop at Jerrod's department store if they were offered the convenience of shopping carts. In fact, even if the amount spent by these additional customers only just covered the cost of providing the carts, providing carts would still probably increase Jerrod's profits, since _______.

In a certain wildlife park, park rangers are able to track the movements of many rhinoceroses because those animals wear radio collars. When, as often happens, a collar slips off, it is put back on. Putting a collar on a rhinoceros involves immobilizing the animal by shooting it with a tranquilizer dart. Female rhinoceroses that have been frequently recollared have significantly lower fertility rates than uncollared females. Probably, therefore, some substance in the tranquilizer inhibits fertility.

In evaluating the argument, it would be most useful to determine which of the following?

Most of Western music since the Renaissance has been based on a seven-note scale known as the diatonic scale, but when did the scale originate? A fragment of a bone flute excavated at a Neanderthal campsite has four holes, which are spaced in exactly the right way for playing the third through sixth notes of a diatonic scale. The entire flute must surely have had more holes, and the flute was made from a bone that was long enough for these additional holes to have allowed a complete diatonic scale to be played. Therefore, the Neanderthals who made the flute probably used a diatonic musical scale.

In the argument given, the two portions in boldface play which of the following roles?

Until now, only injectable vaccines against influenza have been available. Parents are reluctant to subject children to the pain of injections, but adults, who are at risk of serious complications from influenza, are commonly vaccinated. A new influenza vaccine, administered painlessly in a nasal spray, is effective for children. However, since children seldom develop serious complications from influenza, no significant public health benefit would result from widespread vaccination of children using the nasal spray.

Which of the following is an assumption on which the argument depends?

In Kravonia, the average salary for jobs requiring a college degree has always been higher than the average salary for jobs that do not require a degree. Over the last few years, the number of Kravonians enrolled in college has been growing steadily. Therefore, the number of Kravonians entering the job market who have at least the qualification of a college degree will eventually be significantly higher than it has been over the last few years.

Which of the following, if true, most seriously weakens the argument?