小学、初中、高中各种试卷真题知识归纳文案合同PPT等免费下载www.doc985.com课时作业(八)Unit3SectionⅡGrammarandusage&IntegratedskillsⅠ.阅读理解APeoplewhoaregoodatgrowingplantsknowthatit'spossibletoplantwhatseemstobealifelessstickandproduceatreeorotherkindsofplants.Thestickisreallywhatiscalledahardwoodcutting.Fromthesecuttings,trees,vines(藤蔓)exceptpinetreescangrow.Theyarecalledhardwoodbecausethepiecesarewoodyratherthanleafy.Gardenerscanexpectcloseto100percentsuccesswithplantssuchasgrape,gooseberry,privet,spiraeaandhoneysuckle.However,thismethoddoesnotworkwithapple,mapleoroaktrees,forexample.Becausetheylackleaves,hardwoodcuttingsarelessperishable(易腐烂的)thansoftwoodcuttings.Ifyouwanttodevelopagreenthumb—orgetreallygoodatgrowingplants—startyoureffortwithhardwoodcuttingsofwillow.Willowtreesoftenspreadfrombranchesthattakerootontopofthegroundthroughthewinter.Mostotherplantsdemandalittlemoreattention.Autumnisagoodtimetostarthardwoodcuttings.First,choosesomeshoots(新枝)thatgrewduringthemostrecentgrowingseason—theyoungestshoots.Cuttheshootstoalengthofabout15centimeters.Makesureyourememberwhichendwasup—theendthatisfartherfromtheroot.Expertsdothisbycuttingthebottomsoffdirectlyandthetopsatananglesotheyavoidmistakesduringplanting.Then,placethebottomofeachcuttingintosomewell－drained(排水良好的)soil.Ifyouhavetoplantinthespring,thecuttingsneedtobekeptcoolandwetthroughthewinter.Thetraditionalmethodistoplacethecuttingstogetherandburythemupsidedowninthesoil.Thisletsthebottomsofthecuttingsbefirsttofeelthewarmingeffectsofspringsunontheground.Putthecuttingsinaclosedplasticbag,putawetpapertowelaroundthebag,andthenputthewholethinginanotherplasticbag.1．Whatcanwelearnaboutwoodyplantsaccordingtothetext?A．Gardenerscanget100%successwiththem.B．Thecuttingsfromthemdryoutbeforerootsform.C．Allwon'tgrowfromhardwoodcuttings.D．They'refarlessreliablethanleafyplants.2．Whichofthefollowingfitsthemethodofhardwoodcuttingsproperly?A．Appletrees.B．Oaktrees.C．Pinetrees.D．Willowtrees.3．Whatisthefourthparagraphmainlyabout?A．Howtomakecuttings.B．Whentomakecuttings.C．Wheretoputcuttings.D．Whattomindatchoosing.4．Whatdoestheauthorstressaboutcuttingsinthelastparagraph?A．Thechoice.B．Thestorage.小学、初中、高中各种试卷真题知识归纳文案合同PPT等免费下载www.doc985.comC．Thetemperature.D．Theseasons.BToday,Chinahasconducteditsfirst3Dprintingexperimentinspaceinanewlylaunchedspacecraft,whichwasputintolow－EarthorbitbyChina'sLongMarch5Bheavyliftcarrierrocket.VideobroadcastonCCTVshowedthattheprinterhasprintedaflatsectionofahoneycomb－shaped(蜂巢状的)structureaswellasasymbolofChinaAerospaceScienceandTechnologyCorp,theparentcompanyoftheChinaAcademyofSpaceTechnology.Theexperimentwasdonebya3Dprinter,developedandbuiltbyitsBeijingSpacecraftsManufacturingFactoryinsidetheprototypeofChina'snew－generationmannedspacecraft.Theprinter,namedtheSpace－BasedCompositeMaterial3DPrintingSystem,usescarbonfiber－reinforcedmaterialstoautonomouslyprintobjects.Itisinstalledinthereentrymoduleoftheexperimentalspaceship,andwillbebroughtbacktoEarthoncethemodulereturns.Theprinterfeaturesadvancedtechnologiesinmaterialmodeling,precisioncontrolandautomation.Oncethespace－based3Dprintingtechnologybecomesoperationallyready,itcanextensivelybenefitspaceprogramsasastronautscanuseittomanufacturealotofthingstheycurrentlyneedtoobtainfromresupplyflig...