（A） Since the risk to insurers of satellites is spread over relatively few units, insurance premiums are necessarily very high.
（B） When satellites reach orbit and then fail, the causes of failure are generally impossible to pinpoint with confidence.
（C） The greater the performance demands placed on satellites, the more frequently those satellites break down.
（D） Most satellites are produced in such small numbers that no economies of scale can be realized.
（E） Since many satellites are built by unwieldy international consortia, inefficiencies are inevitable.
17.Tocqueville, a nineteenth-century writer known for his study of democracy in the United States, believed that a government that centralizes power in one individual or institution is dangerous to its citizens. Biographers claim that Tocqueville disliked centralized government because he blamed Napoleon's rule for the poverty of his childhood in Normandy.Which of the following, if true, would cast the most serious doubt on the biographers' claim?
（A） Although Napoleon was popularly blamed at the time for the terrible living conditions in Normandy, historians now know that bad harvests were really to blame for the poor economic conditions.
（B） Napoleon was notorious for refusing to share power with any of his political associates.
（C） Tocqueville said he knew that if his father had not suffered ill health, his family would have had a steady income and a comfortable standard of living.
（D） Although Tocqueville asserted that United States political life was democratic, the United States of the nineteenth century allowed political power to be concentrated in a few institutions.
（E） Tocqueville once wrote in a letter that, although his childhood was terribly impoverished, it was not different from the experience of his friends and neighbors in Normandy.
18.Radio interferometry is a technique for studying details of celestial objects that combines signals intercepted by widely spaced radio telescopes. This technique requires ultraprecise timing, exact knowledge of the locations of the telescopes, and sophisticated computer programs. The successful interferometric linking of an Earth-based radio telescope with a radio telescope on an orbiting satellite was therefore a significant technological accomplishment.Which of the following can be correctly inferred from the statements above?
（A） Special care was taken in the launching of the satellite so that the calculations of its orbit would be facilitated.
（B） The signals received on the satellite are stronger than those received by a terrestrial telescope.
（C） The resolution of detail achieved by the satellite-Earth interferometer system is inferior to that achieved by exclusively terrestrial systems.
（D） The computer programs required for making use of the signals received by the satellite required a long time for development.
（E） The location of an orbiting satellite relative to locations on Earth can be well enough known for interferometric purposes.
19.Recent estimates predict that between 1982 and 1995 the greatest increase in the number of people employed will be in the category of low-paying service occupations. This category, however, will not increase its share of total employment, whereas the category of high-paying service occupations will increase its share.If the estimates above are accurate, which of the following conclusions can be drawn?
（A） In 1982 more people were working in low-paying service occupations than were working in high-paying service occupations.
（B） In 1995 more people will be working in high-paying service occupations than will be working in low-paying service occupations.
（C） Nonservice occupations will account for the same share of total employment in 1995 as in 1982.
（D） Many of the people who were working in low-paying service occupations in 1982 will be working in high-paying service occupations by 1995.
（E） The rate of growth for low-paying service occupations will be greater than the overall rate of employment growth between 1982 and 1995.
20.For a local government to outlaw all strikes by its workers is a costly mistake, because all its labor disputes must then be settled by binding arbitration, without any negotiated public-sector labor settlements guiding the arbitrators. Strikes should be outlawed only for categories of public-sector workers for whose services no acceptable substitute exists.The statements above best support which of the following conclusions?
（A） Where public-service workers are permitted to strike, contract negotiations with those workers are typically settled without a strike.
（B） Where strikes by all categories of pubic-sector workers are outlawed, no acceptable substitutes for the services provided by any of those workers are available.
（C） Binding arbitration tends to be more advantageous for public-service workers where it is the only available means of settling labor disputes with such workers.
（D） Most categories of public-sector workers have no counterparts in the private sector.
（E） A strike by workers in a local government is unlikely to be settled without help from an arbitrator.
参考答案：
1. D 2. E 3. E 4. D 5. C
6. B 7. B 8. D 9. C 10.E
11.D 12.E 13.C 14.A 15.A
16.C 17.C 18.E 19.A 20.C
