页眉内容根据工程勘察报告揭露,本场地自地表至持力层深度范围内所揭露的土层主要由饱和粘土、砂土组成,具有成层分布的特点。页脚内容现在完成时1.构成现在完成时是由助动词have(has)+动词的过去分词构成。助动词have(has)表明事情发生于现在。它和主语的人称、数要保持一致。过去分词在句子中做谓语,说明句子的含义。2.用法(1)动作发生在过去某个不确定的时间,但对现在有某种影响和结果。常被just、already、yet等副词修饰。如:-Haveyouhadlunchyet?-Yes,Ihave.I'vejusthadit.你(已经)吃午饭了吗?我刚刚吃过。(现在我不饿了)(2)表示从过去某一时刻开始一直持续到现在的动作或状态。这个动作可能刚停止,可能仍然在进行。常带有for和since等表示一段时间的状语。如:Hehastaughtheresince1981他自1981年就在这儿教书。(可能还要继续教)Ihave'tseenherforfouryears.我有四年没见到她了。(3)表示说话前发生过一次或多次的动作,现在成为一种经验,一般译为汉语“过”,常带有twice,ever,never,threetimes等时间状语。如:IhavebeentoBeijingtwice.我去过北京二次。3.现在完成时的时间状语(1)现在完成时属于现在时范围,故不能和过去的时间状语连用。如:yesterday,lastSunday,in1990,threeyearsago等。但是,在强调动作产生的后果和影响时,可以和一些表示不确定的时间状语连用。a.用副词already和yet。already一般用于肯定句中,yet一般用于否定句和疑问句中。如:Wehavealreadyfinishedourhomework.我们已完成作业了。Theyhaven'tfinishedtheirhomeworkyet.他们还没有完成作业。b.用ever和never。多用于否定或疑问句中,表示“曾经”或“从未“等。如:-HaveyoueverbeentotheGreatWall?你曾经去过长城吗?-IhaveneverbeentotheGreatWall.我从未去过长城。c.用表示到说话为止的过去时间状语,如just,before,uptonow,thepastfewyears等。例如:Ihaveseenherbefore,butIcannotrememberwhere.我以前见过她,但记不起在哪里见过。Hehasbeentherethreetimesthelastfewdays.近几年他去过那里三次了。d.用包括“现在”在内的时间状语,如:now,today,thismorning(month,year,term)等。例如:-Haveyoumethimtoday?-No,Ihaven't.今天你见过他吗?我没有。Howmanytimeshaveyoubeenthere页眉内容根据工程勘察报告揭露,本场地自地表至持力层深度范围内所揭露的土层主要由饱和粘土、砂土组成,具有成层分布的特点。页脚内容thisyear?今年你去过那里多少次?(2)现在完成时可以和带有since或for等表示“一段时间”的状语连用,表示动作或状态从某一时刻开始,一直持续到现在。如:Ihaven'tseenhimfortwoyears.但是,像come,arrive,buy等终止性动词不能与表示“一段时间”的状语连用。要用,必须改为“be(在)”等延续性动词来表述。现归纳总结一下由非延续性动词到延续性动词的转换:arrive→beherebegin(start)→beondie→bedeadcomeback→bebackleave→beawayfallill(sick,asleep)→beill(sick,asleep)getup→beupgoout→beoutfinish→beoverputon→wear或beonopen→beopenjoin→bein或beamemberof…close→beclosedgotoschool→beastudentborrow→keepbuy→havecatch(acold)→have(acold)gettoknow→knowbegintostudy→studycometowork→work等如:Hehasbeenasoldierforthreeyears.他参军三年了。Hisfatherhasbeendeadfortwoyears.他父亲去世二年了。Thefilmhasbeenonfortenminutes.电影已开始十分钟了。WehavestudiedEnglishforthreeyears.我们(开始)学英语已三年了。4.现在完成时和一般过去时的区别现在完成时和一般过去时都表示在过去完成的动作。但现在完成时强调的是这一动作与现在的关系。如对现在产生的结果或影响等,而一般过去时只表示动作在过去某一时刻发生,不表示和现在的关系。试比较:Ihavelostmynewbook.我把新书丢了。(现在还未找到)Ilostmynewbookyesterday.我昨天把新书丢了。(昨天丢的,现在找到与否没说明)5.几点注意事项(1)havebeen(to)与havegone(to)的区别:havebeen(to)表示“去过某地(现在已经回来了)”,可用于各人称;havegone(to)表示“去页眉内容根据工程勘察报告揭露,本场地自地表至持力层深度范围内所揭露的土层主要由饱和粘土、砂土组成,具有成层分布的特点。页脚内容某地了(说话时某人不在当地)”,常用于第三人称,前者可与once,never,severaltimes等连用,后者则不能。如:TheyhavebeentoBeijingtwice.他们去过北京两次。HehasgonetoBeijing.他去北京了。(2)如单纯表示一段时间,或强调一段时间,虽有since一词,也不必用完成时。如:Itistwoyearssincehisfatherdied.=Hisfatherhasbeendeadfortwoyears.他父亲去世已有三年了。(3)终止性动词现在完成时的否定式,已变成一种可以延续的状态,因此可以和表示一段时间的状语连用。如:Ihaven'tleftheresince1997.自从1997年以来,我一直没有离开过这儿。一、单项选择1.LiHonghas________thearmyfor2years.A.joinedB.beinC.beeninD.joinedin2.Wehavebeenfriendssince______.A.childrenB.fiveyearsC.fiveyearsagoD.fiveyearsbefore3.Mike___________thestoryforamonth.A.hasboughtB.hashadC.hadhadD.hasborrowed4.You______thatquestionthreetimes.A.alreadyaskedB.havealreadyaskedC.alreadyhaveaskedD.askedalready5.ThoseforeignfriendsleftGuangzhou__________.A.sincelastweekB.aweekagoC.foraweekD.sinceaweekago6.I_____atthisschoolfortwoyears.A.amstudyingB.studyC.studiedD.havestudied7.They_________inthecitysincelastsummer.A.liveB.didn’tliveC.havelivedD.live8.Mrs.WanghaslivedinHaikou_________1992.A.sinceB.fromC.afterD.in9.Mr.Black_________Chinasincethesummerof1998.A.hasbeentoB.hasbeeninC.hascometoD.cameto10.Hisfather_______foryears.A.hasdiedB.hasbeendeadC.diedD.dies11.Mary________toseethefilmsbecauseshe__________ittwice.A.won’tgo,sawB.won’tgo,willseeC.won’tgo,hasseenD.didn’tgo,sees12.----Wouldyoulikesomemorefood?----Thankyou.I_______enough.A.willhaveB.havehadC.haveD.had13.______you______England?Yes,it_____abeautifulcountry.A.Will,goneto,wasB.Have,beento,isC.Had,beento,isD.Have,goneto,is14.----_______you_______toBeijing?----No,I______.I______thereearlynextmonth.页眉内容根据工程勘察报告揭露,本场地自地表至持力层深度范围内所揭露的土层主要由饱和粘土、砂土组成,具有成层分布的特点。页脚内容A.Have,been,haven’t,amgoingB.Had,been,hadn’t,amgoingC.Have,gone,haven’t,wasgoingD.Did,go,didn’t,wasgoing15.---Yousister______toLondontostudyEnglish.Isthattrue?---Yes,she___therefortwomonths.A.hasbeen,hasbeenB.willgo,hasgoneC.gone,willbeD.hasgone,hasbeen16.Hehasacomputerofhisown.He____ittwodaysagoA.boughtB.boughtC.boughtD.hasbought17.—WhereisLiLei?—He___Shanghai.A.hasgonetoB.hasbeentoC.wenttoD.goesto18.He_______hishomeworkandisnowlisteningtomusic.A..finishesB.hasfinishedC.finishD.isfinishing19.David_______Shanghaiformorethanthreemonths.A.cametoB.hasbeentoC.hasbeeninD.hascometo20.---IsyourfatheraPartymember?---Yes,he____thepartythreeyearsago.He_____aPartymemberforthreeyears.A.joined;hasbeenB.hasjoined;hasbeenC.wasjoined;isD.joined;was21.---Whatanicebike!Howlone____you____it?----Justfiveweeks.A.will;buyB.did;buyC.are;havingD.have;had22.I______thisbookforaweek.Ihavetoreturnitnow.A.borrowedB.haveborrowedC.keptD.havekept23.----______yoursister_______inGreenChinaforalongtime?----Yes.Shejoineditfiveyearsago.A.Has;beenB.Have;beenC.Has;joinedD.Have;joined24.---Howlonghavey