21. On the basis of the premises advanced, which one of the following principles, if established, would provide the most justification for the concluding recommendation？

（A） No segment of a community should be permitted to engage in a practice that has been shown to result in a disproportionate share of police service being devoted to that segment of the community.

（B） When public resources are in short supply, any individual who wants special services from public agencies such as police and fire departments should be required to pay for those services if he or she can afford to do so.

（C） Police departments are not justified in improving service to one segment of the community at the expense of other segments of the community unless doing so reduces the crime level throughout the entire area served.

（D） Anyone who directly benefits from a service provided by public employees should be required to reimburse the general public fund an amount equivalent to the average cost providing that service.

（E） If receipt of a service results in the waste of scarce public resources and people with other legitimate needs are disadvantaged in consequence, the recipient of that service should compensate the public for the resources wasted.

22. When butterfat was considered nutritious and healthful, a law was enacted requiring that manufacturers use the term “imitation butter” to indicate butter whose butterfat content had been diminished through the addition of water. Today, it is known that the high cholesterol content of butterfat makes it harmful to human health. Since the public should be encouraged to eat foods with lower rather than higher butterfat content and since the term “imitation” with its connotations of falsity deters many people from purchasing products so designated, manufactures who wish to give reduced-butterfat butter the more appealing name of “lite butter” should be allowed to do so.

Which one of the following, if true, most seriously undermines the argument？

（A） The manufactures who prefer to use the word “lite” instead of “imitation” are motivated principally by the financial interest of their stock holders.

（B） The manufacturers who wish to call their product “lite butter” plan to change the composition of the product so that it contains more water than it now does.

（C） Some individuals who need to reduce their intake of cholesterol are not deterred from using the reduced-butterfat product by the negative connotations of the term “imitation.”

（D） Cholesterol is only one of many factors that contribute to the types of health problems with which the consumption of excessive amounts of cholesterol is often associated.

（E） Most people deterred from eating “imitation butter” because of its name choose alternatives with a lower butterfat content than this product has.

23. Farm animals have certain behavioral tendencies that result from the evolutionary history of these species. By imposing on these animals a type of organization that conflicts with their behavioral tendencies, current farm-management practices cause the animals more pain and distress than do practices that more closely conform to the animals' behavioral tendencies. Because the animals tend to resist this type of organization, current practices can also be less efficient than those other farm-management practices.

If the statements above are true, which one of the following can be properly inferred from them？

（A） Some of the behavioral tendencies of farm animals can be altered by efficient farm-management practices.

（B） In order to implement efficient farm-management practices, it is necessary to be familiar with the evolutionary history of farm animals.

（C） In order to create farm-management practices that cause less pain and distress to farm animals, a significant loss of efficiency will be required.

（D） Farm-management practices that cause the least amount pf pain and distress to farm animals are also the most efficient management practices.

（E） Some changes in farm-management practices that lessen the pain and distress experienced by farm animals can result in gains in efficiency.

24. It now seems clear that the significant role initially predicted for personal computers in the classroom has not become fact. One need only look to the dramatic decline in sales of computers for classroom use in the past year for proof that the fad has passed.

Which one of the following arguments contains flawed reasoning parallel to that in the argument above？

（A） Clearly government legislation mandating the reduction of automobile emissions has been at least partially successful, as is demonstrated by the fact that the air of the 20 largest cities now contains smaller amounts of the major pollutants mentioned in the legislation than it did before the legislation was passed.

（B） Mechanical translation from one language into another, not merely in narrow contexts such as airline reservations but generally, is clearly an idea whose time has come. Since experts have be4en working on the problem for 40 years, it is now time for the accumulated expertise to achieve a breakthrough.

（C） Sales of computers for home use will never reach the levels optimistically projected by manufacturers. The reason is that home use was envisioned as encompassing tasks, such as menu planning and checkbook reconciliation, that most homemakers perform in much simpler ways than using a computer would require.

（D） It is apparent that consumers have tired of microwave ovens as quickly as they initially came to accept this recent invention. In contrast to several years of increasing sales following the introduction of microwave ovens, sales of microwave ovens flattened last year indicating that consumers have found relatively little use for these devices.

（E） Creating incentives for a particular kind of investment inevitably engenders boom-and-bust cycles. The evidence is in the recent decline in the value of commercial real estate, which shows that, although the government can encourage people to put up buildings, it cannot guarantee that those buildings will be fully rented or sold.

25. Scientists attempting to replicate certain controversial results reported by a group of experienced researchers failed to get the same results as those reported. The conclusion drawn from this by the scientists who conducted the replication experiments was that the originally reported results had been due to faulty measurements.

The argument of the scientists who conducted the replication experiments assumes that

（A） the original experiments had not been described in sufficient detail to make an exact replication possible

（B） the fact that originally reported results aroused controversy made it highly likely that they were in error

（C） the theoretical principles called into question by the originally reported results were themselves based on weak evidence

（D） the replication experiments were not so likely as the original experiments to be marred by faulty measurements

（E） the researchers who originally reported the controversial results had themselves observed those results only once