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在△ABC中,角A,B,C所对的边分别为a,b,c,bsinB+csinC=a(+sinA) (1)求A的大小; (2)若a=,B=,求△ABC的面积
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在△ABC中已知角
,
,
所对的边分别为a,b,c,且a=3,c=8,B.=60°,则△ABC的周长是( ) A.17,B.19,C.16,
18
三角形ABC中角A.BC所对的边分别为abc已知求边C.及面积S.
在△ABC中角ABC所对应的边分别为abc若a=csinA则的最大值为.
在△ABC中角A.B.C.所对的边分别为abc设向量p=a+cbq=b-ac-a若p∥q求角C.的大
已知在△ABC中角A.B.C.所对的边分别为1求△ABC中的最大角2求角C.的正弦值
在△ABC中角A.B.C.所对的边分别为abc.若A.B.C.构成等差数列那么角B.等于.
在△ABC中角A.B.C.所对的边分别为abc已知1求角A.的大小2若a+b=4c=3求△ABC的面
在△ABC中角ABC所对的边分别为abc如果a=2c=A=30°那么△ABC的面积等于.
在△ABC中已知角ABC所对的边分别为abc.若asinA.-sinB.=csinC.-bsinB.
在△ABC中角A.B.C.所对的边分别为abc设S.为△ABC的面积满足则角C.的大小为
.△ABC中角A.B.C.所对的边分别为abca=5b=7B.=60°则c=__________.
在周长为16的三角形ABC中AB=6AB所对的边分别为ab则abcosC的取值范围是.
在△ABC中角A.B.C.所对的边分别为abc若abc成等比数列则角B.的取值范围为.
.在△ABC中角A.B.C.所对的边分别为abc且b2+c2=a2+bc则角A.的大小为.
在△ABC中abc分别为角A.B.C.所对的边若a=2bcosC则此三角形一定是________三角
在△ABC中角A.B.C.所对的边分别为abc若
在△ABC中角A.B.C.所对的边分别为abc且b2+c2=a2+bc则角A.的大小为
在锐角△ABC中abc分别为角A.B.C.所对的边且a=2csinA.角C.=________.
在△ABC中角A.B.C.所对的边分别为abc若a=1∠B=450△ABC的面积s=2.1求边b的长
在锐角△ABC中abc分别为角A.B.C.所对的边且a=2csinA则角C.=________.
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10分 ParentsModelHealthyEating Itshouldcomeasnosurprisethatthemorestressedparentsareatworkthegreatertheburdenontheirfamilyis.1Afterallthemoretimeparentsspendworkingthelesstimeandenergytheyhavetoplanandpreparehealthfulmeals. Foryearsmoststudieshavefocusedontheroleofworkingmotherswhilefatherswereignored.Theydidn'tlookatthefamilyasawhole.2Itaddsanewwrinkletotherelationshipbetweenworkstressandfamilynutrition. Moms'workrelatedstressisstillacentralfactorinhowwellfamilieseatbecausetheytypicallydomostofthefoodshoppingandcooking.3Thestudyfoundthatwhenmomordadexperiencehighlevelsofworkrelatedstresstheirfamiliesareeatingone﹣and﹣a﹣halffewerfamilymealsperweekandtheparentsthemselvesreporteatingfewerfruitsandvegetablesmorefastfoodandarelesslikelytoeatbreakfastregularly. It'sworthnotingthatthestudylookedmainlyatlowincomefamilieswhobelongedtoethnicorminoritygroups.4Buttheimplicationsarewideranging. 5Teachingkidsespeciallyteenagerstohelpwithgroceryshoppingandtocookactualmealsinsteadofjustputtingafrozenpizzainthemicrowavecouldbeanimportantpieceofthepuzzleinhelpingfamiliesimprovestheireatinghabits. A.Butdad'sworkrelatedstresshasalargeimpacttoo. B.Astofamilynutritiontheentirefamilyplaysaroleevenkids. C.Yetthekids'stressmayaffectthefamilies'nutritiontoo. D.Sothefindingsdon'tnecessarilyapplydirectlytoothertypesoffamilies. E.It'salsoprobablynotasurprisethatthiscannegativelyaffectafamily'snutrition. F.Howeverarecentstudydoesandlookattheroleoffathersinparticular. G.Itisparentswhogivetheirkidsagoodmodeltodevelopagoodeatinghabit.
15分Englishisalanguage1bringtoBritaininthe5thcenturybyAnglo﹣SaxonsettlersfromvariouspartsofNorthwestGermany.ItisconvenienttodivideEnglishintothreeperiodsroughly─OldEnglishMiddleEnglishandModernEnglish. The2earlyformofEnglishiscalledOldEnglishorAnglo﹣Saxon.OldEnglishdevelopedfromasetofNorthSeaGermanicdialects3originspokenalongthecoastsofFrisiaLowerSaxonyJutlandandSouthernSwedenbyGermanictribesknown4theAnglesSaxonsandJutes.LaterOldEnglishwasstronglyinfluencedbytheNorthGermaniclanguageNorsespokenbytheVikingswhosettledmainlyinthenorthwest.ThemostfamousworkfromtheOldEnglishperiodistheepicpoemBeowulfwrittenby5unknownpoet.OldEnglishisverydifferentfromModernEnglishanddifficultforthe21st﹣centuryEnglishspeakerstounderstand. Forthe300yearsfollowingtheNormanConquestin1066theNormankingsandthenobilityspokeonlya6varyofFrenchcalledAnglo﹣Norman.Englishcontinuedtobethelanguageofthecommonpeople.TheNormaninfluence7strongthecontinualevolutionofthelanguageoverthefollowingcenturiesresultingin8isnowreferredtoasMiddleEnglish.Andoneofthebest﹣knownworksfromtheMiddleEnglishperiodisGeoffreyChaucer'sTheCanterburyTales. Fromthelate15thcenturythelanguagechangedintoEarlyModernEnglishoftendatedfromtheGreatVowelShift.EnglishiscontinuouslyabsorbingforeignwordsespeciallyLatinandGreekcausingEnglishtohavethelargestvocabularyofanylanguageintheworld.Bythelate18thcenturytheBritishEmpirehadspedthespreadofEnglishthroughitscoloniesandgeopoliticaldominance.CommercescienceandtechnologydiplomacyartandformaleducationallcontributedtoEnglish9becomethefirsttrulygloballanguage.Astherearemanywordsfromdifferentlanguagestheriskofmispronunciationishigh.In1755SamuelJohnsonpublishedhisADictionaryoftheEnglishLanguage10introducedastandardsetofspellingconventionsandusagenorms.
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