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In a certain state, over 80% of the land is comprised of farms, but historically, large farm machinery has not sold well in this state. The percentage of land devoted to farms is not expected to increase. In fact, the number of farms in the state has been slowly declining over the past decade. A new manufacturer of large farm equipment is building a factory in the middle of this state, and the manufacturer's plans for success depend on strong in-state sales of their product. Both the manufacturer and the industry analysts are expecting this manufacturer to be quite successful over the next few years.
Which of the following, if true, most helps to provide a justification for the manufacturer's and the industry analysts' optimistic expectations?
Operations at the Green Hills Gold Mine are continuously releasing mercury into the headwaters of the Apache River, and most fish in the Apache River now have mercury levels at or above the legal limit for human consumption. With the price of gold rising, forcing more and more mining at Green Hills, there seems no hope for food fishing along the Apache River.
Which of the following plans, if feasible, would allow the state to assist the food fishing industries along the Apache?
In 1995, ecologists started to reintroduce the wolf into Yellowstone Park, where the wolf had been eliminated intentionally half a century earlier. Rangers expected a rise in the number of wolf would place limits on the elk population and on the populations of many mid-size mammals. One unexpected consequence was a dramatic rise in the population of foxes, which in turn helped to control many rodent populations.
Which of the following, if true, most helps explain the dramatic rise in the fox population?
NewTech clothes dryers, a new line of dryers that uses 1/3 the energy of traditional dryers, recently took over as the leading dryer-in terms of the number of units sold-in the nation of Imperia. This season, NewTech is expanding into the nation of Sumonia, producing 10,000 units for sale in the country. The company believes that the NewTech dryer will quickly sell out in Sumonia, leading the company to export more units before years end.
Which of the following, if true, suggests that NewTechsdryers will not sell as well in Sumonia as the company expects?
The ponerines are the most diverse of all the ant groups and are global in distribution. They cannot really be thought of as sophisticated superorganisms, though, for they tend to live in small colonies of a few tens to a few thousand individuals, with one Australian species living in colonies of just a dozen. Like Stone Age human hunters who specialized in killing woolly mammoths, the ponerines tend to specialize in hunting one or a few kinds of prey. That the great success of the ponerines is achieved despite their primitive social organization presents entomologists with what is known as the ponerine paradox. It lacks a widely accepted solution, but researchers suspect that the ponerines predilection to seek specialized types of prey limits their colony size (for such specialized hunters cannot gather enough food to develop large and sophisticated colonies). If this is the case, then the very characteristic that helps the ponerines to diversify and survive in a wide variety of environments also prevents them from attaining superorganism status.
In the context in which it appears, "predilection" most nearly means
Phytonutrients, found in fresh fruits and vegetables, have beneficial effects on the human cardiovascular system. Because heart disease is a major health concern, American doctors should encourage all people, especially those with heart disease, to eat a diet high in fresh fruits and vegetables.
Which of the following, if true, provides the most support for the argument above?
Political Analyst: "Although citizens of this state normally oppose any new taxes, they are overwhelmingly in favor of taxes that support the medical initiative. Candidate Johnson vowed to cut these taxes, and he was trounced in the primary elections. Furthermore, in a poll that asked citizens, "Would you pay higher taxes if it meant having the benefit of the new medical initiative?" , an astonishing 82% replied "Yes." This is a pattern of support for taxes we have not seen before in this state.
In the political analyst's argument, the portion in boldface plays which of the following roles?
While antibiotics have done inestimable good to humankind over the last seventy years, there are several drawbacks to using antibiotics that, until recently, have been overlooked. The human microbiome, which consists of the trillions of bacteria that reside in each persons body, is essential to good health. Specifically, the body contains and requires both "good" and "bad" bacteria. It is when the proper equilibrium between the "good" bacteria and the "bad" bacteria is disrupted that a number of health issues can emerge. Nonetheless, antibiotics indiscriminately kill both the "good" and the "bad" bacteria, so each course of antibiotics should be followed by a treatment that_____.
Which of the following most logically completes the argument above?
I submit that impact of solid bodies is the most fundamental of all interstellar processes that have taken place on the terrestrial planets: without impact, Earth, Mars, Venus, and Mercury would not exist.

Simply put, the collision of smaller objects is the process by which the terrestrial planets were born. On the surface, that the geological record of the earliest history of impacts on the terrestrial planets has been lost, is troubling. As the process is self-erasing, to a certain extent, the earliest record would have been lost even if processes of melting and internal evolution of the planets had not occurred. But much of the record of the last stages of accretion of the planets is preserved, especially on the moon, Mercury, and Mars. In fact, the last stage of accretion is still going on, albeit at a very slow rate.

This is fortunate, because we can study many aspects of the processes of planetary birth by investigation of the nature of small bodies that still exist, the dynamics of their orbital evolution, and the effects that they produce when they ultimately collide with a planet. If impact and accretion were not still occurring, it would be hard to come to grips with a number of difficult problems of planetary origin and early evolution.
It can be most reasonably inferred that which of the following accounts for the lack of a geological record concerning the history of impacts on the planets?
Sleep-learning experiments are notoriously difficult to conduct. For one thing, one must be sure that the subjects are actually asleep and stay that way during the "lessons." The most rigorous trials of verbal sleep learning have failed to show any new knowledge taking root. While more and more research has demonstrated the importance of sleep for learning and memory consolidation, none had managed to show actual learning of new information taking place in an adult brain during sleep.

Recently, however, researchers chose to experiment with a type of conditioning that involves exposing subjects to a tone followed by an odor, so that they soon exhibit a similar response to the tone as they would to the odor. The pairing of tones and odors presented several advantages. Neither wakes the sleeper (in fact, certain odors can promote sound sleep), yet the brain processes them and even reacts during slumber. Moreover, the sense of smell holds a unique non-verbal measure that can be observed -- namely sniffing. The researchers found that, in the case of smelling, the sleeping brain acts much as it does when awake: We inhale deeply when we smell a pleasant aroma but stop our inhalation short when assaulted by a bad smell. This variation in sniffing could be recorded whether the subjects were asleep or awake. Finally, this type of conditioning, while it may appear to be quite simple, is associated with some higher brain areas -- including the hippocampus, which is involved in memory formation.

In the experiments, the subjects slept in a special lab while their sleep state was continuously monitored. As they slept, a tone was played, followed by an odor -- either pleasant or unpleasant. Then another tone was played, followed by an odor at the opposite end of the pleasantness scale. Over the course of the night, the associations were partially reinforced, so that the subject was exposed to just the tones as well. The sleeping volunteers reacted to the tones alone as if the associated odor were still present -- by either sniffing deeply or taking shallow breaths. The next day, the now awake subjects again heard the tones alone -- with no accompanying odor. Although they had no conscious recollection of listening to them during the night, their breathing patterns told a different story. When exposed to tones that had been paired with pleasant odors, they sniffed deeply, while the second tones -- those associated with bad smells -- provoked short, shallow sniffs.

The team then asked whether this type of learning is tied to a particular phase of sleep. In a second experiment, they divided the sleep cycles into rapid eye movement (REM) and non-REM sleep, and then induced the conditioning during only one phase or the other. Surprisingly, they found that the learned response was more pronounced during the REM phase, but the transfer of the association from sleep to waking was evident only when learning took place during the non-REM phase. The researchers suggest that during REM sleep we may be more open to influence from the stimuli in our surroundings, but so-called "dream amnesia" -- which makes us forget most of our dreams -- may operate on any conditioning occurring in that stage of sleep. In contrast, non-REM sleep is the phase that is important for memory consolidation, so it might also play a role in this form of "sleep-learning.
The first paragraph serves primarily to
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