打印机为什么在使用一时间后,就频繁出现打印机吸入打印纸后打印纸不动而只有打印头来回移动
有可能搓纸轮搓纸能力下降,造成搓纸不到位,纸张不能到达字辊处,不能继续向前走,所以出现打印纸不动而只有打印头来回移动的现象。
暂无解析
PartIReadingComprehension
Passage1
Questions1to5arebasedonthefollowingpassage:
InWashingtonD.C.,1600PennsylvaniaAvenueisaveryspecialaddress.ItistheaddressoftheWhiteHouse,thehomeofthepresidentoftheUnitedStates.
OriginallytheWhiteHousewasgrayandwascalledthePresidentialPalace.Itwasbuiltfrom1792to1800.atthistime,thecityofWashingtonitselfwasbeingbuilt;itwastobethenation’snewcapitalcity.GeorgeWashington,thefirstpresident,andPierreCharlesL’Enfant,aFrenchengineer,chosetheplaceforthenewcity.L’Enfantthenplannedtheycity.Thepresident’shomewasanimportantpartoftheplan.
Acontestwasheldtopickadesignforthepresident’shome.AnarchitectnamedJamesHobanwon.Hedesignedalargethree-storyhouseofgraystone.
PresidentWashingtonneverlivedinthePresidentPalace.ThefirstpresidenttolivetherewasJohnAdams,thesecondpresidentoftheUnitedStates,andhiswifeMrs.Adamsdidnotreallylikehewnewhouse.Inherletters,sheoftencomplainedaboutthecold.Fiftyfireplaceswerenotenoughtokeepthehousewarm!
In1812theUnitedStatesandBritainwenttowar.In1814theBritishinvadedWashington.Theuburnedmanybuildings,includingthePresidentialPalace.
AfterthewarJamesHoban,theoriginalarchitect,partiallyrebuiltthepresident’shomes.Tocoverthemarksofthefire,thebuildingwaspaintedwhite.BeforelongitbecameknownastheWhiteHouse.
TheWhiteHouseisoneofthemostpopulartouristattractionsintheUnitedStates.Everyyearmorethan1.5millionvisitorsgothroughthefiveroomsthatareopentothepublic.
1.TheWhiteHousewasbuiltinWashington.
A.becauseaFrenchengineerwasinvitedtodesignit
B.becausePresidentGeorgeWashingtonlikedtoliveinit
C.becausetheBritishinvaderslivedinitin1812-1814
D.becauseitwastobethenation’scapitalcity
2.ThePresidentialPalacewas.
A.paintedgrayandwhiteB.madeofgraystone
C.madeofwhitestoneD.madeverywarminwinter
3.Thepresident’shomeandthecityofWashingtonwere.
A.builtbytheAmericanarmyB.builtbytheBritishtroops
C.plannedbyGeorgeWashingtonD.plannedbytheFrench
4.Theoriginalhomeofthepresidentneededtoberebuilt.
A.becauseJohnAdam’swifedidnotlikeit
B.becauseitwascoldinwinterevenwith50fireplaces
C.becauseithadburneddownduringthewar
D.becauseGeorgeWashingtonwasnotwillingtoliveinit
5.Thenewpresidentialhomewaspaintedwhiteto.
A.coverthemarksoffireB.attracttouristfromFrance
C.topleaseMrs.JohnAdamsD.keepitwarminwinter
Scatteredthroughtheseasoftheworldarebillionsoftonsofsmallplantsandanimalscalledplankton.Mostoftheseplantsandanimalsaretoosmallforthehumaneyetosee.Theydriftaboutlazilywiththecurrents,providingabasicfoodformanylargeranimals.Planktonhasbeendescribedastheequivalentofthegrassesthatgrowonthedrylandcontinents,andthecomparisonisanappropriateone.Inpotentialfoodvaluehowever,planktonfaroutweighsthatofthelandgrasses.Onescientisthasestimatedthatwhilegrassesoftheworldproduceabout49billiontonsofvaluablecarbohydrateseachyear.Thesea’splanktongeneratesmorethantwiceasmuch.
Despiteitsenormousfoodpotential,littleeffortwasmadeuntilrecentlytofarmplanktonaswefarmgrassesonland.Nowmarinescientistshaveatlastbeguntostudythispossibility,especiallyasthesea’sresourcesloomevenmoreimportantasameansoffeedinganexpandingworldpopulation.
Nooneyethasseriouslysuggestedthat“planktonburgers”maysoonbecomepopulararoundtheworld.Asapossiblefarmedsupplementaryfoodsource,however,planktonisgainingconsiderableinterestamongmarinescientists.
Onetypeofplanktonthatseemstohavegreatharvestpossibilitiesisatinyshrimplikecreaturecalledkrill.Growingtotwoorthreeincheslong,krillprovidethemajorfoodforthegiantbluewhale,thelargestanimalevertoinhabittheEarth.Realizingthatthiswhalemaygrow100feetandweigh150tonsatmaturity,itisnotsurprisingthateachonedevoursmorethanonetonofkrilldaily.
Krillswimaboutjustbelowthesurfaceinhugeschoolssometimesmileswide,mainlyinthecoldAntarctic.Becauseoftheirpinkcolor,theyoftenappearasasolidreddishmasswhenviewedfromashiporfromtheair.Krillareveryhighinfoodvalue.Apoundofthesecrustaceanscontainsabout460calories—aboutthesameasshrimporlobster,towhichtheyarerelated.
Ifthekrillcanfeedsuchhugecreaturesaswhales,manyscientistsreason,theymustcertainlybecontendersasnewfoodsourceforhumans.
1.Whichofthefollowingbestportraystheorganizationofthepassage?
A.Theauthorpresentstheadvantagesanddisadvantagesofplanktonasafoodsource.
B.Theauthorquotespublicopiniontosupporttheargumentforfarmingplankton.
C.Theauthorclassifiesthedifferentfoodsourcesaccordingtoamountofcarbohydrate.
D.Theauthormakesageneralstatementaboutplanktonasafoodsourceandthenmovestoaspecificexample.
2.Accordingtothepassage,whyisplanktonregardedtobemorevaluablethanlandgrasses?
A.Itiseasiertocultivate.
B.Itproducesmorecarbohydrates.
C.Itdoesnotrequiresoil.
D.Itismorepalatable.
3.Whydoestheauthormention“planktonburgers”?
A.Todescribetheappearanceofonetypeofplankton.
B.Toillustratehowmuchplanktonawhaleconsumes.
C.Tosuggestplanktonasapossiblefoodsources.
D.Tocomparethefoodvaluesofbeefandplankton.
4.Whatismentionedasoneconspicuousfeatureofkrill?
A.Theyarethesmallestmarineanimals.
B.Theyarepinkincolor.
C.Theyaresimilarinsizetolobsters.
D.Theyhavegrasslikebodies.
5.Theauthormentionsallofthefollowingasreasonswhyplanktoncouldbeconsideredahumanfoodsourceexceptthatitis___.
A.highinfoodvalue.
B.inabundantsupplyintheoceans.
C.anappropriatefoodforotheranimals.
D.freeofchemicalsandpollutants.
Theministeroffinanceisbelieved_____ofimposingnewtaxestoraiseextrarevenue.
Thismountainrangehasmanyhigh_____andfertilevalleys.
翻译:
如今,中国正步入老龄化社会,因此独生子女一代面临着巨大的工作和生活压力。中国政府开始适当调整计划生育政策,允许一些家庭在特殊情况下生育二胎。但调查显示,很多夫妻迫于不断加重的经济压力,放弃生育二胎。因此,要从根本上解决老龄化的问题不能依靠出生率的上升,最有效的办法是建立有效的社会保障制度。