小结(xiǎojié)That充当关系(guānxì)代词，取代who,whom,which使用that的情况：1、当先行(xiānxíng)词是nothing,something,anything,all,each等不定代词时。eg.Doyouhaveanythingthatisimportanttotellme?2、当先行(xiānxíng)词被all,any,some,no,not,every,each等修饰时。eg.Ihavesomebooksthatareverygood.3、当先行(xiānxíng)词被形容词最高级、序数词所修饰时。eg.ThisisthefirstbookthatIboughtmyself.ThebiggestbirdthatIcaughtisthisbird.4、当先行词被thevery,thelast,thenext,theonly等词修饰时。eg.ThisistheverybookthatIlostyesterday.5、当先行词又有人又有物时。eg.Iwon’tforgetthethingsandthepersonsthatIsaw.6.避免与疑问词重复(what,where,when,how,which,who)Whoisthemanthatisstandingthere?7.两个(liǎnɡɡè)相同的关系代词引导定语从句，避免重复使用同一个关系代词。Heworkshard,whichisafactthatisknowntous.As引导的定语(dìngyǔ)从句五、关系代词as和whichas和which所代表的都是整个句子所表示的内容。有两点不同之处：１、在形式上as引导的非限制定语(dìngyǔ)从句可位于主句后面，也可位于主句之前；而which引导的非限制定语(dìngyǔ)从句只能位于主句之后，不能位于主句的前面。２、在意义上，as定语(dìngyǔ)从句和主句的关系一般为一致关系，常译为“正......”，“就象.....”，而which定语(dìngyǔ)从句和主句的关系是因果关系，或which从句是对主句的评论。因此，在意思通顺的情况下，which可代替as，而as许多时候不能代替which。Hewaslateagain,as/whichwehadexpected.=Aswehadexpected,hewaslateagain.1.______wasnatural,hemarriedJenny.A.WhichB.ThatC.ThisD.As2.Suchsigns_____weuseintheexperiment______Greekletters.A.as,areB.as,isC.that,areD.that,is3.Ipassedhimalargeglassofwhisky,_____hedrankimmediately.A.thatB.asC.whichD.who4.Sheisverygoodatdance,____everybodyknows.A.thatB.whichC.whoD.as5.Itwasraining,_____wasapity.A.whatB.thatC.thewhichD.which6.______hasbeensaidabove,grammarisasetofdeadrules.A.WhichB.WhatC.ThatD.As7.Wedothesamework_____theydo.A.whichB.asC.thanD.like8.Theearthisround,_____weallknow.A.thatB.whichC.whoD.as1A.Isthisthefactory_____youvisitedlastyear?B.Isthisfactory____youvisitedlastyear?a.thatb.wherec.inwhichd.theone2.A.MrSmithisoneofthoseforeignerswho____workinginChina.B.MrSmithistheonlyoneofthoseforeignerswho____workinginChina.a.isb.hasc.haved.are5.A.Pisaisacity,___hasaleaningtower.B.Pisaisacity,____thereisaleaningtower.a.whichb.thatc.whered.there6.A.Thisistheplace____wevisitedlastyear.B.Thistheplace____weworkedl