2007年GMAT考试最新逻辑推理仿真试题训练十五(4)
（A） A***hough it sells all of the telepho***s that it produces, Mammoth Industries' share of all telepho*** sales has dec******d over the last year.
（B） Mammoth Industries' **erage ***ven***ry of telepho***s await***g ship***nt *** retailers has dec******d s***ghtly over the last year.
（C） Advertis***g has made the brand na*** of Mammoth Industries' telepho***s widely known, but few ***nsu***rs know that Mammoth Industries owns this brand.
（D） Mammoth Industries' telepho*** is o*** of three brands of telepho*** that h**e ***gether a***ount*** f*** the bulk of the last year's ***crease *** sales.
（E） Despite a s***ght dec****** *** the retail pr***e, sales of Mammoth Industries' telepho***s h**e fallen *** the last year.
17.Many ***stitutions of higher ***ucation suffer dec***n***g enroll***nts dur***g periods of e***nom*** slowdown. At two-year ***mmunity ***lleges, however, enroll***nt figures boom dur***g these periods when many people h**e less mo***y and there is m***e ***mpetition f*** jobs.Each of the follow***g, if true, helps *** expla*** the enroll***nt ***creases *** two-year ***mmunity ***lleges describ*** above EXCEPT:
（A） Dur***g periods of e***nom*** slowdown, two-year ***mmunity ***lleges are m***e ***kely than four-year ***lleges *** prepare their students f*** the jobs that are still **ailable.
（B） Dur***g periods of e***nom*** prosperity, graduates of two-year ***mmunity ***lleges often ***nt***ue their studies at four-year ***lleges.
（C） Tuition at most two-year ***mmunity ***lleges is a fraction of that at four-year ***lleges.
（D） Two-year ***mmunity ***lleges devote m***e resources than do other ***lleges *** attract***g those students especially affect*** by e***nom*** slowdowns.
（E） Students at two-year ***mmunity ***lleges, but not those at most four-year ***lleges, can ***ntrol the ***st of their studies by choos***g the number of ***urses they take each term.
Questions 18-19 are bas*** on the follow***g.
Hard*** argu*** that graz***g land held *** ***mmon （that is, open *** any user） would always be us*** less carefully than private graz***g land. Each rancher would be tempt*** *** overuse ***mmon land bec***se the be***fits would a***rue *** the ***di***dual, while the ***sts of r***uc*** land qua***ty that resu***s from overuse would be spread among all users. But a study ***mpar***g 217 mil***on acres of ***mmon graz***g land with 433 mil***on acres of private graz***g land ***w*** that the ***mmon land was *** better ***ndition.
18.The answer *** wh***h of the follow***g questions would be most useful *** evaluat***g the signif***ance, *** relation *** Hard***'s claim, of the study describ*** above?
（A） Did any of the ranchers whose land was studi*** use both ***mmon and private land?
（B） Did the ranchers whose land was studi*** tend *** prefer us***g ***mmon land over us***g private land f*** graz***g?
（C） Was the private land that was studi*** of ***mparable qua***ty *** the ***mmon land bef***e either was us*** f*** graz***g?
（D） Were the users of the ***mmon land that was studi*** at least as prosperous as the users of the private land?
（E） Were there any ow***rs of herds who us*** o***y ***mmon land, and no private land, f*** graz***g?
19.Wh***h of the follow***g, if true, and known by the ranchers, would best help expla*** the resu***s of the study?
（A） With private graz***g land, both the ***sts and the be***fits of overuse fall *** the ***di***dual user.
（B） The ***st *** r***uc*** land qua***ty that is attributable *** any ***di***dual user is less easily ***asur*** with ***mmon land than it is with private land.
（C） An ***di***dual who overuses ***mmon graz***g land might be able *** achieve higher returns than other users can, with the resu*** that he *** she would obta*** a ***mpetitive advantage.
（D） If o*** user of ***mmon land overuses it even s***ghtly, the other users are ***kely *** do so even m***e, with the ***nsequence that the ***sts *** each user outweigh the be***fits.
（E） There are m***e acres of graz***g land held privately than there are held *** ***mmon.
20.In tests f*** pironoma, a serious disease, a false po***ive resu*** ***d***ates that people h**e pironoma when, *** fact, they do not; a false ***gative resu*** ***d***ates that people do not h**e pironoma when, *** fact, they do. To detect pironoma most a***urately, phys***ians ***uld use the lab***a***ry test that has the lowest prop***tion of false po***ive resu***s.Wh***h of the follow***g, if true, gives the most supp***t *** the re***m***ndation above?
（A） The a***ept*** treat***nt f*** pironoma does not h**e damag***g side effects.
（B） The lab***a***ry test that has the lowest prop***tion of false po***ive resu***s c***ses the sa*** m****** side effects as do the other lab***a***ry tests us*** *** detect pironoma.
（C） In treat***g pironoma patients, it is essential *** beg*** treat***nt as early as possible, s***ce even a week of delay can resu*** *** loss of ***fe.
（D） The prop***tion of ******nclusive test resu***s is equal f*** all lab***a***ry tests us*** *** detect pironoma.
（E） All lab***a***ry tests *** detect pironoma h**e the sa*** prop***tion of false ***gative resu***s.
参考解答：
1.E 2.A 3.B 4.D 5.C
6.A 7.A 8.B 9.E 10.B
11.A 12.A 13.E 14.B 15.B
16.E 17.B 18.C 19.D 20.E