英语四级段落信息匹配题及答案.docx
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英语四级段落信息匹配题及答案
英语四级段落信息匹配题及答案
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我根据大家的需要整理了一份关于《英语四级段落信息匹配题及答案》的内容,具体内容:
如英语俨然也成为了一门必修必须掌握的学科,英语四级已经成为大学生们很基本的一门考试了,今天我在这里为大家分享一些英语四级段落信息匹配题,欢迎大家阅读!
英语四级段落信息匹配题...
如英语俨然也成为了一门必修必须掌握的学科,英语四级已经成为大学生们很基本的一门考试了,今天我在这里为大家分享一些英语四级段落信息匹配题,欢迎大家阅读!
英语四级段落信息匹配题篇1
Paper--MorethanMeetstheEye
A)Wearesurroundedbysomuchpaperandcardthatitiseasytoforgetjusthowcomplexitis.Therearemanyvarietiesandgradesofpapermaterials,andwhilstitisfairlyeasytospotthevarieties,itisfarmoredifficulttospotthegrades.
B)Itneedstobeunderstoodthatmostpaperandcardismanufacturedforaspecificpurpose,sothatwhilstthecorn-flakepacketmaylooksmart,itisclearlynotsomethingdestinedforthearchives.Itismadetolookgood,butonlyneedsalimitedlifespan.Itisalsomuchcheapertomanufacturethanhighgradecard.
C)Papercanbemadefromanalmostendlessvarietyofcellulose-basedmaterialwhichwillincludemanywoods,cottonsandgrassesorwhichpapyrusisanexampleandfromwherewegettheword"paper".Manyoftheseareveryspecialized,butthepreponderanceofpapermakinghasbeenfromsoftwoodandcottonorrags,withthebulkbeingwood-based.
PaperfromWood
D)Inordertomakewoodintopaperitneedstobebrokendownintofinestrands.Firstlybypowerfulmachineryandthenboiledwithstrongalkaliessuchascausticsoda,untilafinepulpofcellulosefibersisproduced.Itisfromthispulpthatthefinalproductismade,relyingonthebondingtogetherofthecelluloseintolayers.That,inaverysmallnutshell,istheessenceofpapermakingfromwood.However,therealityisrathermorecomplicated.Inordertogiveusourwhitepaperandcard,themakerswilladdbleachandothermaterialssuchaschinaclayandadditionalchemicals.
E)Afurtherproblemwithwoodisthatitcontainsamaterialthatisnotcellulose.Somethingcalledlignin.Thisisessentialforthetreesinceitholdsthecellulosefibrestogether,butifitisincorporatedintothemanufacturedpaperitpresentsarchivistswithaproblem.Lignineventuallybreaksdownandreleasesacidproductsintothepaper.Thiswillweakenthebondbetweenthecellulosefibersandthepaperwillbecomebrittleandlookratherbrownandcareworn.Wehaveallseenthisinoldnewspapersandcheappaperbackbooks.Ithasbeenestimatedthatmostpaperbackbookswillhavealifeofnotgreaterthanfiftyyears.Notwhatweneedforourarchives.
F)Sincethelignincanberemovedfromthepaperpulpduringmanufacture,theobviousquestionis"whyisitleftinthepaper?
"Theanswerliesinthefactthatligninmakesupaconsiderablepartofthetree.Byleavingthelignininthepulpapapermakercanincreasehispaperyieldfromatreetosome95%.Removingitmeansayieldofonly35%.Itisclearlyuneconomictoremovetheligninformanypaperandcardapplications.
G)Italsomeans,ofcourse,thatlignin-freepaperisgoingtobemoreexpensive,butthatisneverthelesswhatthearchivistmustlookforinhissupplies.Thereisnopointwhatsoeverincarefullyplacingourvaluableartifactsinpaperorcardthatisgoingtohastentheirdemise.Acidisparticularlyharmfultophotographicmaterials,causingthemtofadeandissomecasessimplyvanish!
H)So,howdowetellapieceofsuitablepaperorcardfromonethatisunsuitable?
Youcannotdoitbysimplylooking,andratherdisappointingly,youcannotalwaysrelyonthelabel."Acid-free"mightbetrueinasmuchasatestonthepapermayindicatethatitisaneutralmaterialatthistime.Butlignincantakeyearsbeforeitstartstheinevitableprocessofbreakingdown,andintherightconditionsitwillspeedupenormously.
I)Addedtothis,asIhaveindicatedearlier,papermayalsocontainothermaterialsaddedduringmanufacturesuchasbleach,chinaclay,chemicalwhitenersandsize.Thislookslikeableakpicture,anditwouldbebutforthefactthattherearesupplierswhowillguaranteethematerialthattheysell.Ifyouwanttobeabsolutelysurethatyouarestoringin,orprintingon,thecorrectmaterialthenthisisprobablytheonlyway.
J)Incidentally,acidscanmigratefrommaterialtomaterial.Liningoldshoeboxeswithgoodqualityacid-freepaperwilldolittletoguardthecontents.Theacidwillgetthereintheend.
PaperfromRag
K)Paperisalsocommonlymadefromcottonandragwaste.Thishastheadvantageofbeinglignin-free,butbecausethereismuchlesscottonandragthantrees,italsotendstobemuchmoreexpensivethanwoodpulppaper.Youwillstillneedtopurchasefromareliablesourcethough,sinceevenragpaperandcardcancontainundesirableadditives.
L)Areliablesourceforqualityragpapersisarecognizedartstockiest.Manywatercolorartistsinsistonusingonlyfinequalityragpaperandboard.
M)Themainlessontolearnfromthis