高中英语Unit4Breakingboundaries突破语法大冲关外研版

Unit4Breakingboundariesit作形式主语[察看例句]1．ItisdifficultforaforeignertolearnChinese.2．It'skindofyoutohelpme.3．Itisnousetalkingtohimaboutit.4．Itisamysterytomehowitallhappened.5．Itisbelievedthatthefloodthereisthebiggestin100years.[概括用法]it作形式主语时没有详细的意义，不过帮助把真实的主语移到句子后边去，使句子显得均衡。it作形式主语时，真实的主语往常是不定式短语、-ing短语或主语从句。一、不定式短语作真实的主语，常用于以下句型中：It

＋

be

＋形容词

＋

(for/ofsb.)todosth.It

＋be

＋名词＋

todosth.Ittakessb.sometimetodosth.

干花了某人时间It'suptosb.todosth.干是某人的职责或义务Itiseveryone'sdutytoobeythelaw.恪守纪律是每一个人的义务。Ittookthemayeartobuildthebridge.建这座桥花了他们一年的时间。Itisbadmannerstostareatpeople.盯着人看是不礼貌的。Itisuptoustohelpthoseinneed.帮助那些有困难的人是我们的责任。[名师点津

]在“It＋

be＋形容词＋for/ofsb.to

dosth.

”句型中，假如形容词描绘的是

sb.，则应用介词of；假如描绘的是

todosth.

就用

for

。It'snecessaryforustouseashort

-waveradiotopickuptheprogrammes.我们用一台短波收音机收听这些节目是必需的。It'simportantforustolearnEnglishwell.学好英语对我们来说是重要的。Itwasfoolishofhimtogiveupthejob.(＝Hewasfoolishtogiveupthejob.)他放弃那工作是愚笨的[即学即练1]用所给词的适合形式填空Itisnotuptoyoutotell(tell)mehowtodomyjob.Itisnotrighttouse(use)theseplacesasrubbishdumps.Itwasniceofthemtoinvite(invite)us.二、-ing

短语作真实主语的状况远不及不定式短语那么广泛，

常限于nogood,nouse,useless,waste

等词的后边。Itisnogood/usehavingacarifyoucan'tdrive.有车假如不会开是没实用途的。ItisawasteoftimewatchingTV.看电视是浪费时间的。Itisnouseaskinghim.问他没实用。[即学即练2]用所给词的适合形式填空①It'snogoodtaking(take)overtheexperienceofforeigncountriesuncritically.It'snousecrying(cry)overspiltmilk.Itisworthmaking(make)anappointmentbeforeyougo.三、用it作形式主语，主语从句作真实主语的常有句型有：1．Itisapity/ashame/afact/anhonour/goodnews/nowonder/awonder...that...Itwasapitythattheengineercouldn'tcome.惋惜工程师没能来。Itisawonderthathecontinuestogamblewhenhealwaysloses!令人吃惊的是他向来输还向来赌。(Itis)nowonder(that)youwerelate!难怪你来晚了！Itisashamethattherainspoiledourpicnic.真惋惜，这场雨把我们的野餐给搅了。ItisafactthatEnglishisbeingacceptedasinternationallanguage.英语被以为是国际语言，这是一个事实。2．Itwonderful/

is＋形容词(如：strange/natural/funny/possible/impossible/likely/

surprising/unlikely/

obvious/clear/

true/fortunate/unusual/certain/important...)＋that...Itiscertainthathewillwin.他必定会取胜。Itisimportantthatweshouldlearnfromeachotherandhelpeachother.我们应该相互学习，相互帮助，这是很重要的。Itwasobviousthatthechildhadbeenbadlytreated.Itislikelythathewillringmetonight.

很明显那个孩子受过凌虐。他今夜可能给我打电话。Itisdoubtfulwhethershewillbeabletocome.她可否来还很难说。3．Itseems/happened/turnedout/

suddenly

struck

me/occurred

to

me...that

...IthappenedthatIwasn'ttherethatday.恰巧那一天我不在那边。Itseemsthathisideaismorepractical.看起来他的建议更实质一些。4．It

＋

be

＋过去分词

(如：

said/reported/announced/decided/expected/hoped/known/believed...)

＋that...Itishopedthatthenumberofdeerwillgreatlyincreaseverysoon.(hopethatthenumberofdeerwillgreatlyincreaseverysoon.)

＝People人们希望鹿的数量会很快增添。Itisreportedthatmorethantwentypeoplewerekilledinthatbusaccident.据报导在那次的公共汽车事故中有二十多人丧生。[即学即练3]用适合的代词填空Itisknownthatheisoneofthebestteachersinourschool.ItsuddenlyoccurredtomethatIknewhowtosolvethatproblem.Itisstrangethatheshouldhaveleftwithouttellingus.Ⅰ.单句语法填空1．Itisverykindofyoutogive(give)meahandintime.2．Itisstillamysterywhatcausedtheaccident.3．Itisnecessarythatone(should)master(master)theskillsofoperatingcomputer.4．ItisknowntoallthatthegunpowderwasfirstinventedbytheChinese.5．Itseemedcertainthathewillwintheprize.Ⅱ.短文语法填空remember(remember)newwordsfirst.Itriedeverymeans,butitnouse3.reciting(recite)themoverandoveragain.Itwasverykindofyou4.tooffer(offer)mesomesuggestions.Itisnecessary5.tounderstand(understand)itsmeaninginsen