2024剑桥雅思讲义Sentence_Completion.docx

ZQ国田IELTSADVANTAGESentenceCompletionPaSSage1ClassesofTreesintheUSAThetimberoftheUnitedStatesisfurnishedbythreewell-definedclassesoftrees:(1)theneedle-leaved,naked-seededconifers,suchaspinezcedarzetc.,(2)thebroad-leavedtreessuchasoak,POPIai;etc.,and(3)toaninferiorextentbythe(one-seedleaf)palmszyuccas,andtheirallies,whichareconfinedtothemostsouthernpartsofthecountry.Broad-leavedtreesarealsoknownasdeciduoustrees,although,especiallyinwarmcountries,manyofthemareevergreen,whiletheneedle-leavedtrees(conifers)arecommonlytermed"evergreens,"althoughthelarch,baldcypress,andothersshedtheirleaveseveryfall,andeventhenames"broad-leaved"and"coniferous,"thoughperhapsthemostsatisfactory,arenotatallexact,fortheconifer"ginkgo"hasbroadleavesandbearsnocones.Amongthewoodsmen,thewoodsofbroad-leavedtreesareknownas"hardwoods,"thoughpoplarisassoftaspinezandthe"coniferouswoods"areknownas"softwoods,"notwithstandingthefactthatyewrankshighinhardnessevenwhencomparedwith"hardwoods".Bothinthenumberofdifferentkindsoftreesorspeciesandstillmoreintheimportanceoftheirproducttheconifersandbroad-leavedtreesfarexcelthepalmsandtheirrelatives.Inthemanneroftheirgrowth,boththeconifersandbroad-leavedtreesbehavealike,addingeachyearanewlayerofwood,whichcoverstheoldwoodinallpartsofthestemandlimbs.Thus,thetrunkcontinuestogrowinthicknessthroughoutthelifeofthetreebyadditions(annualrings),whichintemperateclimatesare,barringaccidents,accuraterecordsofthetree'sage.Withthepalmsandtheirrelativesthestemremainsgenerallyofthesamediametecthetreeofahundredyearsoldbeingasthickasitwasattenyearszthegrowthofthesebeingonlyatthetop.Evenwhereaperipheralincreasetakesplace,asintheyuccas,thewoodisnotlaidoninwell-definedlayersforthestructureremainsirregularthroughout.Thoughalikeinthemanneroftheirgrowth,andthereforesimilarintheirgeneralmake-up,conifersandbroad-leavedtreesdiffermarkedlyinthedetailsoftheirstructureandthecharacteroftheirwood.Thewoodofallconifersisverysimpleinitsstructure,thefibrescomposingthemainpartofthewoodallbeingalikeandtheirarrangementregular.Thewoodofthebroad-leavedtreesiscomplexinstructure;itismadeupofdifferentkindsofcellsandfibresandlackstheregularityofarrangementsonoticeableintheconifers.Thisdifferenceissogreatthatinastudyofwoodstructureitisbesttoconsiderthetwokindsseparately.Inthiscountrythegreatvarietyofwoods,andespeciallyofusefulwoods,oftenmakesthemeredistinctionofthekindorspeciesoftreemostdifficult.Thus,thereareatleasteightpinesofthethirty-fivenativeonesonthemarket,someofwhichsocloselyresembleeachotherintheirminutestructurethatonecanhardlytellthemapart,andyettheydifferinqualityandareoftenmixedorconfoundedinthetrade.Ofthethirty-sixoaks,ofwhichprobablynotlessthansixoreightareQD国IELTSADVANTAGESentence Completionmarketed,wecanreadilyrecognizebymeansoftheirminuteanatomyatleasttwotribes-thewhiteandblackoaks.Thesameistrueoftheelevenkindsofhickory,thesixkindsofashzandsoon.ThelistofnamesofalltreesindigenoustotheUnitedStates,asenumeratedbytheUnitedStatesForestService,is495innumber,thedesignationof"tree"beingappliedtoallwoodyplantswhichproducenaturallyintheirnativehabitatonemain,erectstem,bearingadefinitecrown,nomatterwhatsizetheyattain.TimberisproducedonlybytheSpermatophyta,orseed-bearingplants,whicharesubdividedintotheGymnosperms(conifers),andAngiosperms(broad-leaved).Theconiferorcone-bearingtree,towhichbelongthepines,Iarcheszandfirs,isoneofthethreenaturalordersofGymnosperms.Thesearegenerallyclassedas"softwoods,"andaremoreextensivelyscatteredandmoregenerallyusedthananyotherclassoftimber,andaresimpleandregularinstructure.Theso-called"hardwoods"are"Dicotyledons"orbroad-leavedtrees,asubdivisionoftheAngiosperms.Theyaregenerallyofslowergrowth,andproducehardertimberthantheconifers,butnotnecessarilyso.Basswood,poplar;sycamorezandsomeofthegums,thoughclassedwiththehardwoods,arenotnearlyashardassomeofthepines.Source:https:WWW.autenberq.orci/files/26598/26598-h/26598-h.htm#SEenONIQuestions11-14Completethesentencesbelow.ChooseNOMORETHANONEWORDfromthetextforeachanswer.Writeyouranswersinboxes11-14onyouranswersheet.11. Thebroad-leafedconiferknownas_hasnocones.12. Everyyearthetrunksofconifersandbroad-leavedtreesgetthickerbyadding_whichcanbeusedtotellhowoldthetreeis.13. The_whichconiferwoodiscomposedofareallsimilarandregularlyarranged.14. Oaksareseparatedinto_andblackvarieties.