book6 unit3 Grammar

.,.,1.Itisnevertoooldtolearn.,活到老,学到老。,Lookattheseproverbsandseewhattheyhaveincommon.,.,2.Itrainscatsanddogs.,大雨滂沱,.,3.Itneverrainsbutitpours.,不鸣则已,一鸣惊人。,.,4.Itisapoormousethathasonlyonehole.,.,1.Itisnevertoooldtolearn.2.Itrainscatsanddogs.3.Itneverrainsbutitpours.4.Itisapoormousethathasonlyonehole.,“It”iswidelyusedinEnglish.“It”isveryusefulandcanbeusedinmanyways.,.,Thesubjectposition,ItisamazingthatatmyageIamstillfit.2.Itiseasiertofallthantorise.3.Itisnogoodcryingoverspiltmilk.,“It”canbeusedinthesubjectpositiontostandfor_,_or_.,aclause,aninfinitive,-ingform,Lookatthesentencesandthinkabouttheway“it”isused.,.,Theobjectposition,4.Ithinkitbestthatyoushoulddomoreexercise.5.Hefounditdifficulttoaccustomhimselftogettingupearly.,aclause,aninfinitive,.,ItisamazingthatatmyageIamstillfit.2.Itiseasiertofallthantorise.3.Itisnogoodcryingoverspiltmilk.4.Ithinkitbestthatyoushoulddomoreexercise.5.Hefounditdifficulttoaccustomhimselftogettingupearly.,“It”canbeusedinthesubjectorobjectpositiontostandfor_,_or_.,aclause,aninfinitive,-ingform,.,形式主语句型Its+adj.(possible/necessary/important/easy/strange/naturaltodo/that)Its+n.(pity/honor/shame/wonder)todosth.Its+adj./n.doingsth.Its+-ed+that,.,Ittakessb.sometimetodosth.ItseemsthatItremainsasecret/tobedoneItmatters.Itslikely/unlikelythat.,.,形式宾语句型Make,think,feel,find,consider+it+adj./n.todosth.Like/enjoy/appreciate/dislike/hate/dependon/seeto/takeforgranted+it+从句Iwouldappreciateitifyoucananswermyquestion.Shehatesitwhenyouuseherbooks.Willyouseetoitthatluggageisbroughtback?,.,2.Someyoungpeoplethinktheylookattractivewhentheysmoke.Itseems_,Givingupsmokingisdifficulttodo.Itis_,thatsomeyoungpeoplethinktheylookattractivewhentheysmoke.,difficulttogiveupsmoking.,Rewritethesesentencesusingan“it”structure.,.,3.Mostpeoplebelievesmokingcausescancer.Itisbelieved_4.Donttrytoquitonastressfulday.Itisnouse_,tryingtoquitonastressfulday.,thatsmokingcausescancer.,5.Myfatherhasquitsmokingatlast.Itiswonderful_,thatmyfatherhasquitsmokingatlast.,.,6.Chinaproducesonethirdoftheworldscigarettes.Itisastonishing_7.Youarenotallowedtoadvertisecigarettesinthiscountry.Itisillegal_,thatChinaproducesone-thirdoftheworldscigarettes.,toadvertisecigarettesinthiscountry.,.,8.Youcouldsufferfrombadhealthifyoukeepsmoking.Itislikely_9.Youhavetotakepillstocontrolyourbloodpressure.Itisnecessary_,foryoutotakepillstocontrolyourbloodpressure.,thatyoucouldsufferfrombadhealthifyoukeepsmoking.,.,Itisabeautifulday.2.Itneverrainsbutitpours.3.Itwastimetoquitesmoking.4.Itis10kilometerstothecastle.5.Itweighed4kg.6.Itsverynoisenow.7.ItisFridaytoday.8.ItliesinthesouthofShaoguancity.Itis40!Yougotahighfever!whosknockingatthedoor?Itmightbethemilkman,观察,It可指代时间，距离，温度，日期，天气，重量，长度，环境，方位，性别不明的人、婴儿,.,It/one/that区分,它们均作代词用于指代前文提到的名词。It是同名同物；one和that是同名异物Ilikethebike,butIhavenoenoughmoneytobuyit.Ilikebicycles,butIcantaffordtobuyone.ThebikewhichIwanttobuyismorebeautifulthanthathehas.,.,One为泛指，相当于a/an+名词That为特指，相当于the+名词Achairmadeofsteelisstrongerthatonemadeofwood.ThewaterinthecupishotterthatthatinthepotOne只能代替可数名词单数，代替可数名词复数用ones;that既可代替不可数名词可以代替可数名词单数，代替可数名词复数用those,.,Ilikearedpe