高一必修二：Unit 3 reading 知识点讲解

高一必修二：Unit3reading知识点讲解unit3computer学问点讲解

原创人：北大附中河南分校王萍

1.ibeganasacalculatingmachineinfrancein1642.

translate：__________________________________________________

现在分词作定语可以表示修饰词的性质，特征。现在分词通常表示主动意思

translate:excitingnews________arunningman__________

thetrainleavingatten__________

fallingleaves_______fallenleaves_________

asurprisinglook____________asurprisedlook___________

连接高考：

1the_____lookonherfacesuggestedthatshe______itbefore.

asurprising;wouldn’tknowbsuprising;hadn’tknow

csurprising;hadn’tknowdsurprised;shouldn’tknow

2acommunicativesatellite______asmuchas3.5tonswassentupintospacelastweek.

awighingbweighedctobeweigheddbeingweighed

3scientistshave______thattheworld’spopulationwilldoublebytheendofthiscentury.

anumberedbincludedccalculatedddesigned

2.idevelopedveryslowlyandittooknearlytwohundredyearsbeforeiwasbuiltasananalyticalmachinebycharlesbabbage.

before用于这类句型的结构有：

itdidn’ttake/waslongbefore------过了不久就-----

itwilltake/belongbefore------要过很久----

itwon’ttake/belongbefore------不久-----

translate：

itdidn’ttakelongbeforethefirewasundercontrol

itwillbefiveyearsbeforewemeetagain

选学：

this/itisthefirst/second…time+that从句。that从句一般用现在完成时，假如把前边的is改为was，则that从句用过去完成时。如：

thisisthefirsttimeihavecomehere.

itwasthethirdtime(that)hehadmadethesamemistake.

itis/hasbeen+一段时间+since从句。since从句中用过去完成时。

itwastenyearssincewehadhadsuchawonderfultime.

beabouttodo…when…意为“即将……（这时）突然……”。如：

iwasabouttogooutwhenthetelephonerang.

be(was/were)+doing…when…意为“正在干……（这时）突然……”。

theywerereadingwhentomshoutedinpain.

hardlyhad…done…when…;nosoonerhad…done…than…

when和than从句里用一般过去时，表示