While it is true that effects of disease have been overlooked, the ancient kingdom of People X began to collapse because of the violence, not the new diseases brought by explorers. This much is evident from the fact that the kingdom first fell in the south, in the region under attack by explorers, and only later in the northern part of the kingdom.

Which of the following, if true, would most strengthen the argument above?

If the city goes on polluting the air at present rates, air quality and visibility over the city will begin to suffer, rainwater may be polluted, and the city will contribute to the global problem of greenhouse emissions. Taxing every polluting commercial establishment per volume of polluted air or per particulate volume of greenhouse emissions will induce businesses to reduce the amount of pollution they emit; this charge will therefore protect the city's air.

Which of the following is an assumption made in drawing the conclusion above?

In the face of consumer demands, many agricultural companies in this country have stopped growing genetically modified strains of some of their crops and resumed growing unmodified strains of those crops. Clearly, less genetically modified produce is being farmed in this country as a result of this switch than would have been farmed if those companies had continued to produce the genetically modified variants.

Which of the following, if true, most strengthens the argument above?

The value of gold has crashed; will it ever return to its previous high within the next year? Even at around $60, the value of gold is still up over 100 percent since it matched its last all-time high in the low $30 range just two months ago. One trend is clear, at $60 or at $250, the ecosystem of watching and trading gold continues to expand. Within the next year, without a doubt, more portfolios will include gold, more companies will be created to serve people who consider trading gold, and more people will buy gold. Clearly, it can be concluded that gold will go up.

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

Which of the following most logically completes the argument?

A particular computer virus frequently infects personal computers through an email message. Even though virus-scanning software installed on a computer is designed to identify and alarm the user of a virus infection on that computer shortly after it occurs, this particular virus is rarely observed by virus-scanning software. This fact, however, does not mean that the computer's security systems have blocked installation of the virus, because _______________.

The founders of a new company believe they have developed a new standard of DVD that will display movies at far higher fidelity than any existing standard. While they recognize that the benefits of the new technology may not be sufficient to induce the entire market to adopt the new player and disc formats, they predict that the format will be worth the cost of adoption in commercial venues that show movies on large screens, where the improvement in quality would be quite noticeable.

Which of the following, if true, would most weaken the conclusion drawn above?

Which of the following most logically completes the passage?

In cars, airbags provide good protection for the chest and head, but little or no protection for legs. A study of injuries resulting from car accidents showed that a large proportion were caused by blows to the legs. Therefore, if air bags protected this area, the risk of serious injury in car accidents would be greatly reduced, especially since _______________.

Given that, recently, the founders of startup company Zeddifreddo have confirmed that they are in the late stages of discussion of an acquisition offer from another company, other potential acquirers of the company, who had suspected that Zeddifreddo's business performance was mostly hype and not a product of sound financials, have taken interest in making their own acquisition offers. They figure that, if Zeddifreddo's current potential acquirer has reached late stages of an acquisition discussion without having withdrawn its bid, that the acquirer must have had a chance to audit Zeddifreddo's financial position and has found it to be sound. Such reasoning might be hasty, however, since potential acquirers of a startup have been known to overlook that company's financial soundness and favor the acquisition on other grounds, however ill-advised such a position may be.

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

Recycled plastic lumber is a building material made from plastic bottles and other plastic waste. Unlike traditional lumber, it won't rot or absorb water, and it is highly resistant to insect damage, so it is well-suited for marine and outdoor applications. Recycled plastic lumber is worth considering as an alternative to traditional lumber for most building projects, with the exception of interior residential projects.

Which of the following, if true, most helps to explain the exception noted above?

Last year the rate of unemployment was 8.2 percent, but this year it has been 7 percent. We can conclude that unemployment is on a downward trend and the rate will be even lower next year.

Which of the following, if true, most seriously weakens the conclusion above?

The design of an ancient pyramid suggests that the population who built the structure had developed the solar calendar. The exterior walls of the partly ruined pyramid consist of four successive stairways, and if a platform at the top of the structure is imagined as a single step atop four stairways of 91 steps each, the total number of steps corresponds to the number of days in the year according to the solar calendar.

Which of the following, if true, most strongly supports the hypothesis?

Which of the following most logically completes the argument below?

A non-profit organization is deciding whether to deliver and administer a limited quantity of a new vaccine for malaria, a mosquito-borne disease, to Country A or Country B, two countries with equal populations that are evenly distributed geographically and equally at risk of malaria. The expected rate of success per administration is expected to be the same in each country, but the non-profit organization has limited time to administer the drug and is uncertain of reaching either population in its entirety. Country B is smaller. Therefore, administering the vaccine to Country B will be more effective than administering to Country A, since _______________.

Which of the following most logically completes the argument?

The city is threatened by an impending tropical storm, which is expected to raise the water outside the city to levels approaching the height of the protective barrier along the coast. Three teams of engineers and oceanographers have independently predicted the maximum water level will reach 89%, 83%, and 88% of the height of the protective barrier. The city is sufficiently safe, provided that _______________.

Disease X has afflicted cattle and cut into ranchers' profits. A genetic cause of the disease has been identified, as well as a gene therapy that can completely eradicate the cause of the disease in cattle. By applying this gene therapy to their cattle and eradicating the genetic susceptibility to the disease, ranchers will be able to carry on business in the future without incidence of Disease X in their cattle.

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

Inhabitants of the country Orctania suffer from a much lower incidence of cancer than the inhabitants of other countries, for reasons that are generally theorized to be environmental and behavioral--the pollution-free air, stress-free and drug-free living, healthy dietary practices, and active lifestyle. Nevertheless, people from other countries who take up residence in Orctania and attempt to follow the practices of the inhabitants still have a radically higher incidence of cancer than do native Octanians.

Which of the following does NOThelp to explain the higher incidence rate of cancer in non-native Orctanians?

The percentage of global tourists who visit Glastock has increased by five percentage points over the past three years. Since tourism contributes an estimated 7% of Glastock's gross domestic product, this increase is likely to have a positive impact on the economy of Glastock.

Which of the following, if true, most strengthens the argument given?

Fund manager: over the last five years, the various stock funds managed by our company increased on average by 7 percent more in value than the market as a whole annually. Furthermore, the performance of each particular stock fund has not varied much from one year to the next, and our few investment products other than stock funds have stayed even with the market. These results show the success of our company: each year, most of our investment products have increased in value more than the market.

The debater's argument is most vulnerable to criticism on which of these grounds?

Cattle rancher: The new government regulations requiring the testing of all cattle crossing state borders would cost cattle ranchers $1 billion annually. These regulations would damage the nation's economy.

Health regulator: Some of the $1 billion spent or lost by ranchers will be revenue for other businesses. Profits will be gained as well as lost.

The health regulator responds to the cattle rancher by

A statistical review of word types and frequencies in all of the novels in a library has found that the novels published prior to 1970 use far fewer slang words, measured as a percentage of the book's total words, than the novels published in 1970 or later. Evidently, whether or not they intended to do so, authors of novels published prior to 1970 used less slang than authors of later books.

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

A number of college students were recruited by the psychology department to participate in a paid, unspecified experiment, which turned out to be a menial, monotonous counting exercise. Unbeknownst to the students, half of the participants were paid a meager rate for their participation, while half received a generous rate. After the counting exercise was complete, each student was asked questions on his or her perception of the counting exercise. Surprisingly, the participants who had been paid less reported higher levels of enjoyment in completing the exercise than the higher-paid participants did.

Which of the following hypotheses, if true, best accounts for the findings of the experiment?