過去完成時(shí)Thepersonwhoansweredthecallwasnotthecaptain’sfirstchoice.Itwasayoungmanwhohadleftmedicalschoolwithoutcompletinghisdegree.

...hehadrecentlyreceivedaletterfromhisfatherpredictingthathe

wouldbe“adisgracetoyourselfandallyourfamily.2.AfterDarwinhadspentsometimeinSouthAmerica,hisroomontheshipwascrowedwithsamplesoftheplantsandanimalshehadcollected.

（花時(shí)間和收集樣本在先hadspent;hadcollected，

房間被樣本塞滿在后wascrowdedwith）（輟學(xué)在先hadleft，響應(yīng)號(hào)召在后answered）（收到父親來信在先hadreceived，響應(yīng)號(hào)召在后answered）3.Atthattime,peoplebelievedthatallspecieshadappearedonEarthatthesametime,andhadnotchangedsince.4.Itseemedtheirbeakshadevolvedaccordingtowhatfoodwasavailableonthatparticularisland.5.Overtime,ithadslowlyevolvedintomanynewspecies.（出現(xiàn)和不改變發(fā)生在前hadappeared；hadnotchanged相信這個(gè)事實(shí)在后believed）（鳥嘴進(jìn)化發(fā)生在前hadevolved，達(dá)爾文注意到這個(gè)現(xiàn)象在后seemed）（慢慢進(jìn)化發(fā)生在前hadevolved，達(dá)爾文發(fā)現(xiàn)鳥類有所不同發(fā)生在后）什么是過去完成時(shí)？

過去完成時(shí)由“had+過去分詞”構(gòu)成。表示在過去的某一時(shí)間或某一動(dòng)作之前完成的動(dòng)作或存在的狀態(tài)，即“過去的過去”。句中常用by,before,until,when等詞引導(dǎo)時(shí)間狀語。NowPastPastperfect過去完成時(shí)haddone一般過去時(shí)

動(dòng)詞過去式在我們到達(dá)車站之前，火車就已經(jīng)走了。Beforewegottothetrainstation,thetrainhadalreadyleft.到上學(xué)期期末為止，我們已經(jīng)學(xué)了2000個(gè)英語單詞了。Bytheendoflastterm,we__________________________________.

gotto/arrivedathadgone/leftbylasttermhadlearnedhadlearned2000Englishwords.注意：在以下兩個(gè)特殊句型hardly…when…和nosooner…than…“（A）剛一...，（B）就...”主句要部分倒裝，并使用過去完成時(shí)，從句用一般過去時(shí)e.g.:1.HardlyhadIleftwhenitbegantorain.我剛離開就開始下雨了。（先離開，再下雨）2.Nosoonerhadhesatdownthanthephonerang.他剛坐下，電話鈴就響了。（先坐下，鈴才響）我剛學(xué)完這一單元的單詞，我就忘了。HardlyhadIlearnedthevocabularyinthisunitwhenIforgotallofthem.表示愿望、打算等的動(dòng)詞，如hope,want,expect,think,mean,suppose,intend,plan等后接從句時(shí)，一般用過去完成時(shí)表示本打算實(shí)現(xiàn)而未實(shí)現(xiàn)的愿望和計(jì)劃。比較一下兩句話：Ihopeyouwillpasstheexam.Ihopeyouhadpasstheexam.我希望你（下次）能通過考試。我真希望你通過了（上次）的考試。實(shí)際沒通過可能會(huì)通過a.Naturaldisastersledtofoodshortagesinthe1960s.b.YuanLongpingbegantodoresearchonhybridrice.c.YuanLongpingdevelopedabettertypeofrice.YuanLongping_____________todoresearchonhyaridricebecausenaturaldisasters______________foodshortagesinthe1960s.Intheend,he____________abettertypeofrice.beganhadledtodevelopeda.GregorMendelchosetostudypeaplantsbecausetheircharacteristicswereeasytocontrol.b.GregorMendelmadeimportantdiscoveriesaboutgenetics.c.GregorMendeldiedin1884GregorMendel___________studypeaplantsbecausetheircharacteristicswereeasytocontrol.Bythetirmeofhisdeathin1894,he___________________discoveriesaboutgenetics.chosetohadmadeimportantcompetedecline eatliveintroduce arriveLonesomeGeorgewasthelastPintaIslandtorroise.Hediedin2012.AfterGeorge'sdeath,thePintaIslandtortoisewasdeclaredexinct.TheextinctionofthePintaIslandtortoiseisblamedonhumans.Beforehumans__________ontheisland,thespecies___________inislationand___________plantsthatnaturallygrewthere.Georgewasdiscoveredmanyyearsaftertheirarrival,andbythenhumans___________newspeciesthat_________forthefoodthetortoisesate.Aftergoatsinpar