Epidemiologist: Malaria passes into the human population when a mosquito carrying the malaria protozoa bites a human who has no immunity. The malaria parasite can remain for up to forty days in the blood of an infected person. The disease cannot be passed from person to person, unless a non-infected person is exposed to the blood of an infected person. Theoretically, malaria could be eradicated in any given area, if all the mosquitoes carrying malaria in that area are exterminated. If such a course of action is carried out at a worldwide level, then the global eradication of malaria is possible. Which of the following, if true, suggests that the epidemiologist's plan for eliminating malaria is not viable?

The TJ-700 and the Beta Turbomax are two models of cars of different manufacturers. These two models have almost identical specifications and features, and they sell for almost the same price. Both were introduced on the market five years ago, and each year, the respective manufacturers spend about the same amount in advertising. In the past five year, the total number of TJ-700's sold is about 80% greater than the total number of Beta Turbomax's sold. Clearly, the advertising firm that created TJ-700 ads created much more effective ads than the firm that created Beta Turbomax ads. In evaluating the argument, it would be most useful to know which of the following?

From 2005 to 2009, over 80% of graduates from Zenith University were able to secure employment within their first six weeks of graduation. Prospective engineering students should therefore choose Zenith University, if they want to be employed within six weeks of graduating. Which of the following, if true, would most strengthen the argument?

A large number of famous poets in literary history have died under the age of 40 --- Burns, Byron, Keats, Poe, and Shelley, to name a few. By contrast, the large majority of famous painters in art history lived well beyond the age of 40. This difference between famous poets and famous painters is most likely because ____ Which of the following, if true, most logically completes the argument?

Studies have shown that highway drivers are less likely to drive at speeds greater than the posted speed limit if houses or buildings are in some way visible from the road. Assuming similar car, road and traffic conditions, highway drivers are more likely to drive at speeds in excess of the posted speed limit if the natural surroundings are not interrupted by buildings. Psychologists hypothesize that seeing signs of civilization reminds drivers of their responsibility to the safety of their fellow humans, thus making them more likely to obey the posted speed limit. Which of the following, if true, most strongly supports the psychologists' interpretation of the study?

The Canadian elk has traditionally been limited in its geographic range by the presence of elderberries, its primary source of food, which only grow up until a certain point in the tundra. A recent rise in temperatures, however, has seen a spread in the growth of elderberries northwards into the tundra. Therefore, the overall range of the Canadian elk can be expected to increase. Which of the following, if true, best casts doubt on the argument?

In the past decade, two Motorlux models, the T-300, a sports car, and the AG-75, a sports utility vehicle, have been manufactured with the same timing belt, which controls the timing of the engines valves: when the engine is running at a higher RPM, there is more strain on the timing belt. Recent evidence indicates that this particular brand of timing belt has a usable life of about 135,000 miles, somewhat less the 200,000 miles life typical of standard timing belt. Although the same model of timing belt has been used for both models of cars, the incidence of timing belt failure is considerably higher in the AG-75 than in the T-300. This is most likely because ______________________ Which of the following, if true, most logically completes the argument?

A deadly virus that has claimed the lives of local villagers has been traced to the spotted fruit bat, in which the virus resides between periodic outbreaks. Biologists speculate that the bat might also be one of the reservoirs for a number of other viruses that have led to village fatalities. The local government has proposed to eliminate the spotted fruit bat by cutting off passageways that allow the bat to emerge from its caves. Once the bat is unable to emerge from the caves, the government will have achieved its objective of reducing the number of village deaths attributable to viruses. Which of the following, if true, would best indicate that the government's plan will not lead to its objective?

Diomedes Motors has just decided to start using Rapilux Tires on most models of its new cars. The tires cost the same as the previous tires, and the change in tires will not change the sticker price of any car, nor will it change the profit on the sale of any particular car. Nevertheless, the CEO of Diomedes Motors expects this change in tires to increase Diomedes' profits in the coming year.Which of the following, if true, provides the best reason for the expectation?

McCray's Dairy Industries stands to reap tremendous profits in the coming year. The new milking apparatus and packing equipment purchased and installed last year allows McCray's to produce the same quantity of dairy products at less than one third of the previous cost. Restaurants and academic institutions throughout the state will choose to purchase all their dairy products from McCray's, because they will be available at a much lower cost than similar products from rival producers. The argument above assumes which of the following?

An unknown simian virus recently killed off nearly half the human population of a remote jungle town. Because the disease spread at an alarming rate-victims usually exhibited signs within 8 hours of exposure, and many died within 36 hours-the simian virus, if an outbreak occurs again, is likely to cause more deaths than has any other previous virus. Which of the following pieces of information most effectively calls into question the validity of the conclusion?

State politicians are optimistic that the state's economic downturn will not be as severe as had been predicted. Their hopes are bolstered by the data released last week: the jobless rate declined two full percentage points in the last six months. But, many economists have pointed out the flight of unemployed residents to the bordering states where jobs are plentiful. Furthermore, many out of work residents have been rehired at minimum wage: virtually all new jobs in the state in the past year have been minimum wage jobs. Economists cast grave doubts on the economic well-being of the state. In the argument given, the two portions in boldface play which of the following roles?

Bankruptcy is a process that depends on a variety of structural, fiscal, and human variables. These variables are different at every company. Therefore, the pattern of companies declaring bankruptcy should be random. Yet tax records from 2010 demonstrate a pattern: a large number of companies throughout the United States declared bankruptcy at the same time.Which of the following, if true, forms the best basis for at least a partial explanation for the pattern of bankruptcy shown by the tax records?

A company that invests the necessary infrastructure in a large untapped diamond mine can reap as much as 700% profit in the first year. Some of the largest untapped diamond mines in the world are in the nation of Shagoca. Therefore, the American company that brokers a deal in the capital Conkin that allows it to put the necessary infrastructure in place at those mines stands to reap tremendous profits. Which of the following, if true, most helps to explain why American companies are not eager to invest in infrastructure necessarily for diamond mining in Shagoca?

Oceanologist: Recently an unprecedented number of dead dolphins washed ashore along the mid-Atlantic coast. In the blood of over half of the dolphins, marine biologists discovered a brevotoxin that had been emitted by the alga Ptychodiscus brevis, in what is known as a red tide. Additionally, polychlorinated biphenyls (PCB), a toxic industrial compound, was also found in the dolphin's blood. A reasonable conclusion, and indeed one many have drawn, is that the dolphins were simply victims of the brevotoxin. Nonetheless, brevotoxins, by themselves, are not lethal to dolphins, though they do tax the dolphins system. Furthermore, most dolphins have some accumulated brevotoxins in their blood without suffering any ill health effects. Therefore, the brevotoxins alone cannot explain the mass beaching of dead dolphins. Which of the following, if true, does most to help explain the oceanologist's doubt that the brevotoxins were the primary cause of the dolphins washing upon shore?