编辑推荐：名师指导公共英语阅读考试技巧 公共英语pets三级全真模拟试卷 公共英语pets二级语法讲解汇总 09年3月公共英语考生考前互送祝福 Man has been storing up useful knowledge about himself and the universe at the rate which has been spiraling upward for 10000 years. The __1_ took a sharp upward leap with the invention of writing,but even __2_ it remained painfully slow for several centuries.The next great leap forward __3_ knowledge acquisition did not occur __4_ the invention of movable type in the 15th century by Gutenberg and others.__5_ to 1500,by the most optimistic __6_,Europ was producing books at a rate of 1000 titles per year.This means that it __7_ a full century to produce a library of 100000 titles.By 1950,four and a half __8_later,the rate had accelerated so sharply that Europe was producing 120000 ttitles a year._9_ once took a century now took only ten months.By 1960,a __10_ decade later,the rate had made another significant jump,__11_ a century s work could be finished in seven and a half months.__12_,by the mid-sixties,the output of books on a world__13_,Europe included,approached the prodigious figure of 900 titles per day. One can __14_ argue that every book is a net gain for the advancement of knowledge.Nevertheless we find that the accelerative __15_ in book publication does,in fact,crudely __16_ the rate at which man discovered new knowledge.For example,prior to Gutenberg __17_ 11 chemical elements were known.Antimony the 12th,was discovered __18_ the time he was working on his invention.It was fully 200 years since the 11th,arsenic,had been discovered.__19_ the same rate of discovery contioned,we could by now have added only two or three additional elements to the periodic table since Gutenberg.__20_,in the 450 years after the time,certain people discovered some seventy additional elements.And since 1900 we have been isolating the remaining elements not a rate of one every two centuries,but of one every three years. 1) A accumulationB developmentC knowledge D rate 2) A so B if C then D when 3) A to B by C from D in 4) A until B since C when D before 5) A as B due C prior D next 6) A examples B estimates C evidence D evaluation 7) A would take B had taken C was taking D would have taken 8) A decades B centuries C dozens D years 9) A this B these C it D what 10) A plain B historic C single D eventful 11) A now that B so that C as D when 12) A however B but C and D therefore 13) A scope B sphere C scale D stretch 14) A therefore B hardly C accordingly D therefore 15) A line B circle C diagram D curve 16) A fit B like C resemble D parallel 17) A about B only C more thanD less than 18) A in B at C on D for 19) A as B had C if D with 20) A in additionB in turn C instead D in particular 参考答案:来源：考试大 1--5 DAAAC 6--10 BABDC11--15 BCCBD16--20 DBBBC