Increasingly, historians are blaming diseases imported from the Old World for the staggering disparity between the indigenous¹ population of America in 1492-new esti- mates of which soar as high as 100 million, or approxi- (5) mately one-sixth of the human race at that time-and the few million full-blooded Native Americans alive at the end of the nineteenth century. There is no doubt that chronic² disease was an important factor in the precipi- tous decline, and it is highly probable that the greatest (10) killer³ was epidemic⁴ disease, especially as manifested in virgin-soil epidemics⁵.

　　Virgin-soil epidemics are those in which the popula- tions at risk have had no previous contact with the diseases that strike them and are therefore immunologi- (15) cally almost defenseless. That virgin-soil epidemics were important in American history is strongly indicated by evidence that a number of dangerous maladies-small- pox, measles⁶, malaria⁷, yellow fever, and undoubtedly⁸ several more-were unknown in the pre-Columbian (20) New World. The effects of their sudden introduction are demonstrated in the early chronicles of America, which contain reports of horrendous⁹ epidemics and steep population declines, confirmed in many cases by recent quantitative¹⁰ analyses of Spanish tribute records and (25) other sources. The evidence provided by the documents of British and French colonies is not as definitive¹¹ because the conquerors¹² of those areas did not establish permanent settlements and begin to keep continuous records until the seventeenth century, by which time the (30) worst epidemics had probably already taken place. Furthermore, the British tended to drive the native populations away, rather than enslaving them as the Spaniards did, so that the epidemics of British America occurred beyond the range of colonists¹³' direct (35) observation.

　　1. The primary purpose of the passage is to

　　(A) refute a common misconception

　　(B) provide support for a hypothesis

　　(C) analyze¹⁴ an argument

　　(D) suggest a solution to a dilemma¹⁵

　　(E) reconcile opposing viewpoints

　　2. According to the passage, virgin-soil epidemics can be distinguished¹⁶ from other catastrophic outbreaks of disease in that virgin-soil epidemics

　　(A) recur¹⁷ more frequently than other chronic diseases

　　(B) affect a minimum of one-half of a given population

　　(C) involve populations with no prior exposure to a disease

　　(D) usually involve a number of interacting diseases

　　(E) are less responsive to medical treatment than are other diseases

　　3. According to the passage, the British colonists wereunlike the Spanish colonists in that the British colonists

　　(A) collected tribute from the native population

　　(B) kept records from a very early date

　　(C) drove Native Americans off the land

　　(D) were unable to provide medical care against epidemic disease

　　(E) enslaved the native populations in America

4. Which of the following can be inferred from the passage concerning Spanish tribute records?

　　(A) They mention only epidemics of smallpox¹⁸.

　　(B) They were instituted in 1492.

　　(C) They were being kept prior to the seventeenth century.

　　(D) They provide quantitative and qualitative¹⁹ evidence about Native American populations.

　　(E) They prove that certain diseases were unknown in the pre-Columbian New World.

　　5. The author implies which of the following about measles?

　　(A) It is not usually a fatal disease.

　　(B) It ceased to be a problem by the seventeenth century.

　　(C) It is the disease most commonly involved in virgin- soil epidemics.
　(D) It was not a significant problem in Spanish colonies.

　　(E) It affects only those who are immunologically defenseless against it.

　　6. Which of the following can be inferred from the passage about the Native American inhabitants of Ungava Bay?

　　(A) They were almost all killed by the 1952 epidemic.

　　(B) They were immunologically defenseless against measles.

　　(C) They were the last native people to be struck by a virgin- soil epidemic.

　　(D) They did not come into frequent contact with white Americans until the twentieth century.

　　(E) They had been inoculated²⁰ against measles.

　　7. The author mentions the 1952 measles outbreak most probably in order to

　　(A) demonstrate the impact of modern medicine on epidemic disease

　　(B) corroborate²¹ the documentary evidence of epidemic disease in colonial America

　　(C) refute allegations of unreliability made against the historical record of colonial America

　　(D) advocate new research into the continuing problem of epidemic disease

　　(E) challenge assumptions about how the statistical²² evidence of epidemics should be interpreted

　　8. Which of the following, if newly discovered, would most seriously weaken the author's argument concerning the importance of virgin-soil epidemics in the depopulation of Native Americans?

　　(A) Evidence setting the pre-Columbian population of the New World at only 80 million

　　(B) Spanish tribute records showing periodic population fluctuations

　　(C) Documents detailing sophisticated Native American medical procedures

　　(D) Fossils indicating Native American cortact with smallpox prior to 1492

　　(E) Remains of French settlements dating back to the sixteenth century