16. Twenty percent of all energy consumed in the United States is consumed by home appliances. If appliances that are twice as energy- efficient as those currently available are produced， this figure will eventually be reduced to about ten percent.The argument above requires which of the following assumptions？ （A） Home-appliance usage would not increase along with the energy efficiency of the appliances.

（B） It would not be expensive to produce home appliances that are energyefficient.

（C） Home-appliance manufacturers now have the technology to produce appliances that are twice as energy-efficient as those currently available.

（D） The cost of energy to the consumer world rise with increases in the energy efficiency of home appliances.

（E） The percentage of energy consumed by home appliances will increase if existing appliances are not replaced by more energy-efficient models.

17. Inspection system X and inspection system Y， though based on different principles， each detect all product flaws but they each also erroneously reject three percent of flawless products.Since false rejections are very costly， money will by saved by installing both systems， instead of either one or the other， and rejecting only products found flawed by both.

（A） The three percent of flawless products that system X rejects are not all the same products， piece for piece， that system Y erroneously rejects.

（B） It is less costly to accept a flawed product than to rejects a flawless one.

（C） In their price range. System X and Y are the least error-prone inspection systems on the market.

（D）Whichever system performs the second inspection needs to inspect only products not rejected by the first system.

（E） Any way of detecting flaw， other than by using either system X or systemy， requires complete disassembly of the products.

18. Statistics over four consecutive years showed that four percent more automobile accidents happened in California during the week following the switch to daylight saving time and during the week following the switch back to standard time than occurred the week before each event. These statistics show that these time changes adversely affect the alertness of California divers.

The conclusion in the argument above is based on which of the following assumptions？

（A） Drivers in California as well as those in the rest of the United States have similar driving patterns.

（B） The observed increases in accident rates are due almost entirely to an increase in the number of minor accidents.

（C） Four years is not a sufficiently long period of time over which to judge the phenomenon described.

（D） There are no other factors such as school vacations or holiday celebration that cause accident rates to rise during these weeks.

（E） A time change at any other time of years would not produce a similar increase in accident rates.

19. Although the ratio of physicians to total population is about the same in the United States and Canada， the United States has 33 percent more surgeons per capita. Clearly， this is the reason people in the United States undergo 40 percent more operations per capita than do Canadians.

The explanation given above rests on an assumption that

（A） patients in the United States do not have a greater need for surgery than do patients in Canada

（B） the population of the United States is not larger than that of Canada

（C） United States patients sometimes travel to Canada for certain kinds of surgery

（D） General practitioners in the United States do not as a rule examine a who is a candidate for surgery before sending the patient to a surgeon.

（E） There are no unnecessary surgical operations performed in Canada.

Keys： CDEAADA

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