完全二叉樹中，若一個結點沒有______，則它必定是葉子結點
A、右子結點C
暫無解析
Passage2
Questions6to10arebasedonthefollowingpassage:
Thefoodweeatseemstohaveprofoundeffectsonourhealth.Althoughsciencehasmadeenormousstepsinmakingfoodmorefittoeat,ithas,atthesametime,mademanyfoodsunfittoeat.Someresearchhasshowntat40percentofcancerisrelatedtothedietaswell,especiallycancerofthecolon.Differentculturesatemorepronetogetcertainillnessesbecauseofthefoodthatischaracteristicinthesecultures.Thatfoodisrelatedtoillnessisnotanewdiscovery.In1945,governmentresearchersrealizedthatnitratesandnitrites,commonlyusedtopreservecolorinmeats,andotherfoodadditives,causedcancer.Yetthesecarcinogenicadditivesremaininourfood,anditbecomesmoredifficultallthetimetoknowwhichthingsonthepackaginglabelsofprocessedfoodarehelpfulorharmful.Theadditivesthatweeatarenotallsodirect.Farmersoftengivepenicillintobeefandpoultry,andbecauseofthis,penicillinhasbeenfoundinthemilkoftreatedcows.Sometimessimilardrugsareadministeredtoanimalsnotformedicinalpurposes,butforfinancialreasons.Thefarmersaresimplytryingtofattentheanimalsinordertoobtainahigherpriceonthemarket.AlthoughtheFoodandDrugAdministration(FDA)hastriedrepeatedlytocontroltheseprocedures,thepracticescontinue.
6.Howhassciencedoneadisservicetomankind?
A.Becauseofscience,mostofthefoodsweeattodayarecontaminated.
B.Ithascausedalackofinformationconcerningthevalueoffood.
C.Asaresultofscientificintervention,somepotentiallyharmfulsubstanceshasbeenaddedtoourfood.
D.Thescientistshavepreservedthecolorofmeats,butnotofvegetables.
7.Whatarenitratesusedfor?
A.Theypreservesflavorinpackagedfoods.
B.Theypreservethecolorofmeats.
C.Theyaretheobjectsofresearch.
D.Theycausetheanimalstobecomefatter.
8.TheFDAhastriedrepeatedlytocontrol.
A.theattempttofattentheanimals
B.theattempttocuresickanimals
C.theusingofdrugstoanimals
D.theusingofadditivestopreservethedoloroffood
9.Theword“carcinogenic”meansmostnearlythesameas.
A.trouble-makingB.color-retaining
C.money-savingD.cancer-causing
10.WhichofthefollowingstatementsisNOTtrue?
A.Drugsarealwaysgiventoanimalsformedicalreasons.
B.Someoftheadditivesinourfoodareaddedtothefooditselfandsomearegiventothelivinganimals.
C.Researchershaveknownaboutthepotentialhazardsofthefoodadditivesforoverthirty-fiveyears.
D.Foodmaycausefortypercentofcancerintheworld.
PartIVTranslation
Asthesourceofaluminumisalmostinexhaustible,wecanexpectthatmoreandmoreuseswillbefoundforthisversatilemetal.(PassageTwo)
Passage3
Questions11to15arebasedonthefollowingpassage:
TheideaofaspecialdaytohonormotherswasfirstputforwardinAmericain1907.twoyearslaterawoman,Mrs.JohnBruceDodd,inthestateofWashingtonproposedasimilardaytohonortheheadofthefamily—thefather.Hermotherdiedwhenshewasveryyoung,andherfatherbroughtherup.Shelovedherfatherverymuch.
InresponsetoMrs.Dodd’sideathatsameyear—1909,thestategovernorofWashingtonproclaimed(宣布)thethirdSundayinJuneFather’sDay.TheideawasofficiallyapprovedbyPresidentWoodrowWilsonin1916.in1924,PresidentCalvinCoolidgerecommendednationalobservanceoftheoccasion“toestablishmoreintimate(親密)relationsbetweenfathersandtheirchildren,andtoimpressuponfathersthefullmeasureoftheirobligations.”TheredorwhiteroseisrecognizedastheofficialFather’sDayflower.
Father’sDaytooklongertoestablishonanationalscalethanMother’sDay,butastheideagrainedpopularity,tradesmenandmanufacturersbegantoseethecommercialpossibilities.Theyencouragedsonsanddaughterstohonortheirfatherswithsmallthank-youpresents,suchasatieorpairofsocks,aswellasbysendinggreetingcards.
DuringtheSecondWorldWar,AmericanservicemenstationedinBritainbegantorequestFather’sDaygreetingcardstosendhome.ThisgeneratedaresponsewithBritishcardpublishers.ThoughatfirsttheBritishpublicwasslowtoacceptthisratherartificialday,it’snowwellcelebratedinBritainonthethirdSundayinJuneinmuchthesamewayasinAmerica.
Father’sDayseemstobemuchlessimportantasoccasionthantheMother’sDay.Notmanyofthechildrenoffertheirfatherssomepresents.ButtheAmericanfathersstillthinktheyaremuchbetterfatedthanthefathersofmanyothercountries,whohavenotevenadayfortheirsakeinnameonly.
11.WhendidFather’sDayofficiallybegintohavenationalpopularity?
A.1907B.1909C.1916D.1924
12.WhofirststartedtheideaofholdingtheFather’sDay?
A.Mrs.JohnBruceDoddB.Mrs.JohnBruce’sMother
C.ThegovernmentofWashington.D.Somebusinessmen.
13.WhatflowerwillbepopularonFather’sDay?
A.LilyB.WaterLilyC.RedroseorwhiteroseD.Sunflower.
14.Whichstatementistrue,aaccordingtothispassage?
A.IttookevenlongerforMother’sDaytogainnationalpopularity.
B.ThebusinessmenhelpedtomakeFather’sDaypopular.
C.Father’sDayisonlycelebratedinAmerica.
D.Father’sDayisonlyatrickofthebusinessmentomakemoney.
15.WhatwasthefirstreactionoftheBritishpublishingtowardsFather’sDay?
A.Theythoughthighlyofitandaccepteditatonce.
B.Theyjustaccepteditatoncewithoutanyhesitation.
C.Theyjustthoughtitajoke.
D.Theythoughtitwastooartificialandtookalongtimetoaccept.
Milk,butter,andcheeseare____herefromthefarms.
關于接診后期相關內容的描述不正確的是
