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1、__________________________________________________风筝模型：S△ABD:S△BCD=AO:OCS△ABC:S△ADC=BO:ODS1:S3=S2:S4=(S1+S2):(S3+S4)=AO:OCS1:S2=S3:S4=BO:0DS1×S4=S2×S3梯形蝴蝶模型：因为：S1+S2=S1+S4(同底等高)所以：S2=S4因为：S1:S2=S4:S3所以：S1×S3=S2×S4（内项积=外项积）S1:S2:S3:S4:S梯=a2:ab:b2:ab:(a+b)2收集于网络，如有侵权请联
2、系管理员删除__________________________________________________鸟头模型：S△ABC:S△ADE=(AB×AC):(AD×AE)证明：连接BES△ABE:S△ADE=AB:AD---①S△ABC:S△ABE=AC:AE---②①×②得S△ADE:S△ABC=(AB×AC):(AD×AE)燕尾模型：S△ABG:S△ACG=BF:FC证明：因为：S△ABG:S△BGF=S△ACG:S△CGF=AG:GF谓语动词单复数的使用规则收集于网络，如有侵权请联系管理员删除____________
3、______________________________________一般every,each后用单数;all后面的名词是复数.1)名词性从句及不定式、动名词作主语时，谓语动词一般用单数形式。【例如】Tofinishtheworkinadvanceiswhathewants.SmokingcigarettesisdangeroustoyourhealthWhatseemseasyintheoryisdifficultinpractice.Whatcausedtheaccidentisacompletemystery.但是，
4、what引导名词从句作主语时，其表语是复数形式时，系动词也可以是复数形式。【例如】Whatwebadlyneedherearequalifiedteachers.2)当主语是单数，后面跟着由including,with,togetherwith,alongwith,like,inadditionto,aswellas,ratherthan,but,except,morethan,accompaniedby等连接的短语时，谓语动词用单数。【例如】Maryaswellashersisterlikeslisteningtomusic.
5、DoctorRichards,togetherwithhiswifeandthreechildren,istoarriveontheafternoonflight.Mybestfriendratherthananyoneelsehasgotthefirstprizeinthespeechcontest.3)one,oneof,every,everyone,everybody,each,manya,either,neither,noone,nobody,anyone,anybody,someone,somebody用作主语或修饰主
6、语时，谓语动词用单数形式。【例如】Eachman,womanandchildhasthesameright.Manyastudentdoesn’tliketodotheirhomework.(manyastudent＝manystudents)Eitherofstudentsisgoingtocompeteforthepresidentofthestudents’union.Morethanonepersonwasinvolvedinthecase.Neitheroftheyoungmenwhohadappliedforapos
7、itionintheuniversity____.A)hasbeenacceptedB)havebeenacceptedC)wasacceptedD)wereacceptedneither用作主语或修饰主语时，谓语动词用单数形式。此外，定语从句用过去完成时，主句应用一般过去时，故答案为C。收集于网络，如有侵权请联系管理员删除
