Inspection system X and inspection system Y, though based on different principles, each de

ly against the Goths but was defeated, and disappeared mysteriously. Riothamus activities, and only those of Riothamus, match almost exactly those attributed to King Arthur. Therefore, Riothamus must be the historical model for the legendary King Arthur. The argument above requires at least one additional premise. Which of the following could be such a required premise?

A．Modern historians have documented the activities of Riothamus better than those of any other fifth-century king.

B．The stories told about King Arthur are not strictly fictitious but are based on a historical person and historical events.

C．Riothamus" associates were the authors of the original legends about King Arthur.

D．Legends about the fifth century usually embellish and romanticize the actual conditions of the lives of fifth-century nobility.

E．Posterity usually remembers legends better than it remembers the actual historical events on which they are based.

redwood tree. Nevertheless, by observing many trees at different stages, botanists can piece together the evolution of a single tree. Exactly the same principle applies in astronomy to the study of the life-story of globular clusters, huge spherical aggregations of about a million stars all swarming about each other. Which of the following is an assumption made in the passage above?

A．The methods of scientists in one field generally carry over to other fields even if the subject matter is vastly different.

B．Observations of the life cycle of a single individual have little value in scientific studies.

C．Globular clusters at different stages of development are accessible to astronomers for observation and study.

D．There are globular clusters that have not so far been detected by astronomers.

E．Redwoods and globular clusters must both be studied intensively now, while they still exist in sufficient numbers.

will drastically reduce grain production. More optimistic reports, however, point out that, even if such drifts in average temperature do occur, we should expect little change in grain production because there is little evidence that changes in rainfall patterns will occur. Moreover, for most crops, climate-induced yield trends will be masked by both the year-to-year fluctuation of yields and by the enhancement of yields because of technological factors. Which of the following is an assumption on which the more optimistic reports mentioned in the passage are based?

A．Long-range changes in weather patterns cannot be accurately predicted.

B．The growing of grain is so highly dependent on technological factors that improvements in yield are unlikely, regardless of climatic conditions.

C．Trends in rainfall patterns are more difficult to isolate than are trends in temperature.

D．Long-range warming or cooling trends are more damaging to grain production if they are accompanied by changes in rainfall patterns than if they are not.

E．Long-range cooling trends are potentially more destructive to grain production than are long-range warming trends.

culty members retain the royalties from books and articles they write. Therefore, faculty members should retain the royalties from the educational computer software they develop. The conclusion above would be more reasonably drawn if which of the following were inserted into the argument as an additional premise?

A．Royalties from inventions are higher than royalties from educational software programs.

B．Faculty members are more likely to produce educational software programs than inventions.

C．Inventions bring more prestige to universities than do books and articles.

D．In the experience of most universities, educational software programs are more marketable than are books and articles.

E．In terms of the criteria used to award royalties, educational software programs are more nearly comparable to books and articles than to inventions.

, existing pandas should be caplured and placed in zoos around the world. Which of the following statements, if true, casts most doubt on the conclusion drawn above?

A．When in captivity, pandas typically produce more young than they do in their native habitat.

B．Newborn pandas in zoos are not likely to die from infectious diseases, whereas newborn pandas in the wild are likely to die from these diseases.

C．Sufficient quantities of bamboo, the panda"s only food, cannot be made available outside the panda"s native habitat.

D．Many zoos are eager to increase their stock of rare and exotic animals, but there are not enough pandas for all the zoos that want one.

E．Pandas in zoos have as many offspring that survive to adulthood as do pandas in the wild.

lls and pelvic bones of all modern birds. Even though not all dinosaurs have these characteristics , there are scientists who claim that all animals that do have these characteristics are dinosaurs.If the statements above and the claim of the scientists are true, which of the following must also be true?

A．Birds share more characteristics with dinosaurs than they do with other animals.

B．Some ancient dinosaurs were indistinguishable from modern birds.

C．All animals whose skulls share the characteristics of those of modern birds also have pelvic bones that are similar to those of modern birds.

D．Modern birds are dinosaurs.

E．All dinosaurs are birds.

rlines for flying frequently on Bravo airplanes. The coupons are sold to people who pay less for the coupons than they would pay by purchasing tickets from Bravo. This marketing of coupons results in lost revenue for Bravo. To discourage the buying and selling of free-travel coupons, it would be best for Bravo Airlines to restrict the

A．number of coupons that a person can be awarded in a particular year.

B．use of the coupons to those who were awarded the coupons and members of their immediate families.

C．days that the coupons can be used to Monday through Friday.

D．amount of time that the coupons can be used after they are issued.

E．number of routes on which travelers can use the coupons.

zil, two queens in the United States share a nest. Ants from these nests are more aggressive than those from single-queen nests. By destroying virtually all insects in the nest area, these aggressive ants gain sole access to food sources, and the ant population skyrockets. Since certain predator insects in Brazil limit the fire-ant population there, importing such predator insects into the United States would be of overall benefit to the environment by stopping the increase of the fire-ant population in the United States. Each of the following is an assumption made in the argument EXCEPT:

A．The imported insects would not prove more damaging to the environment in the United States than are the fire ants themselves.

B．The predator insects from Brazil could survive in the ecological environment found in the United States.

C．The especially aggressive fire ants from the two-queen nests would not be able to destroy the Brazilian predator insects.

D．The predator insects would stop the increase of the ant population before the ants spread to states that are farther north.

E．The rate of increase of the fire-ant population would not exceed the rate at which the predator insects could kill the ants.

emises of privately owned businesses is an intrusion into the private sector that cannot be justified. The fact that studies indicate that nonsmokers might be harmed by inhaling the smoke from others cigarettes is not the main issue. Rather, the main issue concerns the governments violation of the right of private businesses to determine their own policies and rules. Which one of the following is a principle that, if accepted, could enable the conclusion to be properly drawn?

A．Government intrusion into the policies and rules of private businesses is justified only when individuals might be harmed.

B．The right of individuals to breathe safe air supersedes the right of businesses to be free from government intrusion.

C．The right of businesses to self-determination overrides whatever right or duty the government may have to protect the individual.

D．It is the duty of private businesses to protect employees from harm in the workplace.

E．Where the rights of businesses and the duty of government conflict, the main issue is finding a successful compromise.

of underdeveloped communication skills in children. After-school hours spent playing computer games are hours not spent talking with people. Therefore, children who spend all their spare time playing these games have less experience in interpersonal communication than other children have. The argument depends on which of the following assumptions?

A．Passive activities such as watching television and listening to music do not hinder the development of communication skills in children.

B．Most children have other opportunities, in addition to after-school hours, in which they can choose whether to play computer games or to interact with other people.

C．Children who do not spend all of their after-school hours playing computer games spend at least some of that time talking with other people.

D．Formal instruction contributes little or nothing to children"s acquisition of communication skills.

E．The mental skills developed through playing computer games do not contribute significantly to children"s intellectual development.