Shipping Clerk: The five specially ordered shipments sent out last week were sent out on Thursday. Last week, all of the shipments that were sent out on Friday consisted entirely of building supplies, and the shipping department then closed for the weekend. Four shipments were sent to Truax Construction last week, only three of which consisted of building supplies.

If the shipping clerk's statements are true, which of the following must also be true?

Although most smoking-related illnesses are caused by inhaling the tar in tobacco smoke, it is addiction to nicotine that prevents most smokers from quitting. In an effort to decrease the incidence of smoking-related illnesses, lawmakers in Sandonia plan to reduce the average quantity of nicotine per cigarette by half over the next five years. Unfortunately, smokers who are already addicted to nicotine tend to react to such reductions by smoking correspondingly more cigarettes.

The information above most strongly supports which of the following predictions about the effects of implementing the Sandonian government's plan?

City Official: At City Hospital, uninsured patients tend to have shorter stays and fewer procedures performed than do insured patients, even though insured patients, on average, have slightly less serious medical problems at the time of admission to the hospital than uninsured patients have. Critics of the hospital have concluded that the uninsured patients are not receiving proper medical care. However, this conclusion is almost certainly false. Careful investigation has recently shown two things: insured patients have much longer stays in the hospital than necessary, and they tend to have more procedures performed than are medically necessary.

In the city official's argument, the two boldface portions play which of the following roles?

Economist: Tropicorp, which constantly seeks profitable investment opportunities, has been buying and clearing sections of tropical forest for cattle ranching, although pastures newly created there become useless for grazing after just a few years. The company has not gone into rubber tapping, even though greater profits can be made from rubber tapping, which leaves the forest intact. Thus, some environmentalists conclude that Tropicorp has not acted wholly out of economic self-interest. However, these environmentalists are probably wrong. The initial investment required for a successful rubber-tapping operation is larger than that needed for a cattle ranch. Furthermore, there is a shortage of workers employable in rubber-tapping operations, and finally, taxes are higher on profits from rubber tapping than on profits from cattle ranching.

In the economist's argument, the two boldfaced portions play which of the following roles?

Fish currently costs about the same at seafood stores throughout Eastville and its surrounding suburbs. Seafood stores buy fish from the same wholesalers and at the same prices, and other business expenses have also been about the same. But new tax breaks will substantially lower the cost of doing business within the city. Therefore, in the future, profit margins will be higher at seafood stores within the city than at suburban seafood stores.

For the purposes of evaluating the argument, it would be most useful to know whether

In order to combat Carville's rampant homeless problem, Mayor Bloomfield recently proposed a ban on sleeping outdoors in the city's many parks. He claims that such a measure will force the homeless to either leave Carville or to find means other than sleeping in public parks. Which of the following, if true, suggests that Mayor Bloomfield's plan will be successful?

The Yorgorian people, many of whom still live in the jungle in traditional conditions, eat many meats of jungle mammals, resulting in a cuisine that is high in the protein RX7G, much higher than the cuisine of the industrial nation of Transpraxia. Medical research has shown a high correlation between the protein RX7G and coronary heart disease, and yet, the Yorgorian people have a much lower incidence of such disease than found in Transpraxia. Medical researchers have dubbed this the Yorgorian Paradox. Which of the following, if true, helps to explain the Yorgorian Paradox?

Charcoal from a hearth site in Colorado, 2,000 miles south of Alaska, is known to be 11,200 years old. Researchers reasoned that, since glaciers prevented human migration south from the Alaska-Siberia land bridge between 18,000 and 11,000 years ago, humans must have come to the Americas more than 18,000 years ago.

Which of the following pieces of new evidence would cast doubt on the conclusion drawn above?

Unprecedented industrial growth in the country of Remo has created serious environmental problems because factories there lack adequate pollution-control systems. Remo is developing a clean growth plan that includes environmental regulations that will require the installation of such systems. Since no companies in Remo currently produce pollution-control systems, the plan, if implemented, will create significant opportunities for foreign exporters to market pollution-control systems.

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

People with a certain eye disorder are virtually unable to see in moderately bright light, which seems to them unbearably intense, since the cells of their retinas are overwhelmed by moderately bright light. These people do, however, show normal sensitivity to most components of dim light. Their retinal cells are also not excessively sensitive to red components of moderately bright light.

The information above best supports which of the following hypotheses about people with the disorder described, if they have no other serious visual problems?

Power Plant Spokesperson: "The water quality of the Phage River as it passes through Praseopolis is below federal standards. The citizens of Praseopolis often blame the poor water quality on our coal-burning power plant, which is upstream from Praseopolis. But Vulcan Refinery, along a tributary of the Phage River even further upstream, releases several toxins into the water. Moreover, over 99% of the toxic materials measured in the Phage River in the vicinity of Praseopolis are consistent with metal refining, but not with the by-products of coal combustion." In the power plant spokesperson's argument, the portion in boldface plays which of the following roles?

Sunflowers growing in pots were placed, with their roots submerged, in the pond contaminated with radioactive elements. The sunflowers kept growing; in the process, they absorbed radioactive elements. Within twelve days, 85 percent of the radioactive elements were removed from the water, which is no less than can be accomplished with the much more expensive conventional filtration techniques. Scientists therefore propose using sunflowers for decontamination wherever there are radioactively contaminated ponds.

Which of the following, if true, points to a limitation on the applicability of the proposed method of decontamination?

In the past, most children who went sledding in the winter snow in Verland used wooden sleds with runners and steering bars. Ten years ago, smooth plastic sleds became popular; they go faster than wooden sleds but are harder to steer and slow. The concern that plastic sleds are more dangerous is clearly borne out by the fact that the number of children injured while sledding was much higher last winter than it was ten years ago.

Which of the following, if true in Verland, most seriously undermines the force of the evidence cited?

SafeZone mosquito repellant has been shown in laboratory settings to be effective for twelve hours against the female anopheles mosquito, the only mosquito that transmits malaria. SafeZone, however, is not effective against mosquitoes that do not transmit malaria. The only instance in which SafeZone does not repel the female anopheles mosquito is when this mosquito can detect any ruptured blood vessels, a state that inevitably results whenever any kind of mosquito bites a person. Therefore, assuming one does not have any ruptured blood vessels on their skin before applying SafeZone, that person will not be able to catch malaria for up to twelve hours.Which of the following, if true, would argue most against the use of SafeZone in areas in which malaria is endemic?

Nearly all employees of the factory who have completed their high school diploma have earned their factory safety certificate, having easily completed the eight week training course. The high school graduates who haven't earned the certificate are ones who have evening obligations that have prevented them from taking the course. Overall, though, most of the factory workers have not earned the certificate. If the statements above are true, which one of the following also must be true?