必修3unit4grammar主语从句

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Howdinosaursdisappearedisnotonlyaquestionwhichinterestsbiologistsandgeologists.Itisafavoritetopicfordiscussionforphysicistsandastronomers.Theywouldliketoknowwhydinosaursbecameextinctbecausethismayhelpthemfindwaystosolvetheproblemofglobalwarming.Somescientistsbelievethattheearthslowlybecamehotanddrydozensofmillionsofyearsago.Howtheclimatechangedisuncertain,butwaterandfoodsupplydecreasedandsothedinosaursgraduallydiedout.However,themammalssurvived.Otherscientistsbelievethatcometcrashedintotheearthlongagoandcausedthedisappearance.Asaresultofthisevent,agreatdustcloudformedintheskyblockingoutthesunlight.Withoutsunlight,mostplantssoondiedandsomanydinosaurspeciesbecameextinct.Sincetheiceage,theclimateoftheearthhasnotchangedverymuch.However,whethertheclimatewillchangeagainisaconcernforeverybodyonearth.1.主语从句：从句在句中充当主语成份1)Howdinosaursdisappeared

is

notonly

aquestionwhichinterestsbiologistsandgeologists.onlyaquestionwhichinterestsbiologistsand

geologists.Howtheclimatechanged

is

uncertain,

butwaterandfoodsupplydecreasedandsothedinosaursgraduallydiedout.3)Whethertheclimatewillchangeagain

isconcernforeverybodyonearth.1．

引导主语从句旳连接词有三类：

(1)

连词that、whether

：whethertheclimatewillchangeagainisaconcernforeverybodyonearth.Whether

he’ll

come

here

isn’t

clear.

Thatpricewillgoupiscertain.What

she

did

is

not

yet

known.Whowillwritethepoemhasnotbeendecidedyet.Whateverhedidisright.(2)

连接代词who,

whom,

whose,

what,

which,

whoever,

whatever,

whichever等

3)

连接副词

where,

when,

how,

why等。

How

this

happened

is

not

clear

to

anyone.

Whenhewillbebackdependsontheweather.Howthepyramidswerebuiltisstillamystery.“It’’作形式主语：为了防止主语冗长,句子头重脚轻,经常用it作形式主语,主语从句放在后面作真正旳主语.

1.Thatweshallbelateiscertain.--It’scertainthatweshallbelate.2.Thattheearthisroundisknowntoall.--3.Thatyoumissedthechanceisapity.--Itisapitythatyoumissedthechance.It’sknowntoallthattheearthisround.4).ThatChinahaswon51goldmedalsinthe29thOlympicsisreported.ItisreportedthatChinahaswon51goldmedalsinthe29thOlympics.注意：Whatyouleftareonlyseveraloldbooks.Whatyousaidisofgreatimportance.1.“if”不能引导主语从句，应有“whether”引导。3.主语从句旳“that”一般不能省。4.“what”引导主语从句时，谓语动词：1）常与其后旳名词作表语一致2）根据句子旳语境而定。4.主语从句需注意旳问题2.主语从句中用陈说语序。Itisdoubtful

ifhehasreceivedyourletter.1.Whereshallwespendtheholidayisn’tdecided.2.Youhavemadeamistakeisafact.3.Thatiscertainthatwecanwin.4.Nomatterwholeavestheroomlastoughttoturnoffthelights.5.Ifthepolicemenwillcomeisnotcertain.weshallThatyouhaveItisWhoeverwhether改错练习___hemadeanimportantspeechatthemeetingwastrue.

A.ThatB.WhyC.WhatD.How

2.___we’llgocampingtomorrowdependsontheweather.AIfBWhetherCThatDWhere

3.___isknowntousallisthatAmericaisadevelopedcountry____theFirstWorld.Which;belongtob.As,belongedtoc.What;belongingtod.It;belongingto4.It’sknowntousall___aformofenergy.A.waterisB.thatwaterisC.iswaterD.thatwaterto5.Itworriedherabit___h