资源描述：
《最全雅思流程图汇总.doc》由会员上传分享，免费在线阅读，更多相关内容在应用文档-天天文库。
1、一·Thediagramsbelowshowthestagesandequipmentusedinthecement-makingprocess,andhowcementisusedtoproduceconcreteforbuildingpurposes.·Summarisetheinformationbyselectingandreportingthemainfeatures,andmakecomparsonswherereleant.·Thefirstdiagramindicatesthestagesandeq
2、uipmentintheprocessofmakingcement,andthesecondoneillustrateshowcementandothermaterialsaremixedtoproduceconcreteforbuildingpurposes.·Cementproductioninvolvesthefollowingsteps.Thefirststepistoputlimestoneandclayontwodifferentconveyors.Then,thesetwotypesofmateria
3、lsarepressedintothecrusherwhichbreaksthemintopowder. Afterthat,thepowderispouredintoamixer,andthenmixturesaretransmittedintoarotatingheaterwhichworkswithheat.Thefollowingstepisthatabandcarrierleadstheheatedpowdertoagrinderwherethecementcomesout.Finally,cementi
4、spackedintobags,andtheprocessisfinished.·Concreteproductionismuchmoresimple.Fourdifferentkindsofmaterialsareneededindifferentproportion.Gravelaccountsforthelargestpart,at50%,followedbysand,whichis25%.Cementandwatercontributes15%and10%respectively.Thefourmateri
5、alsarethenmixedandpouredintoaconcretemixerandafteraperiodofwhirling,concreteisproduced.·Inconclusion,makingcementhasmorecomplexprocessthanmakingconcretethoughconcreteneedsmorematerialsthancement.二·Thediagramsbelowshowthelifecycleofthesilkwormandthestagesinthep
6、roductionofsilkcloth.·Summarisetheinformationbyselectingandreportingthemainfeatures,andmakecomparisonswhererelevant.·Thefirstdiagramshowsthattherearefourmainstagesinthelifeofthesilkworm.Firstofall,eggsareproducedbythemothandittakestendaysforeacheggtobecomeasil
7、kwormlarvathatfeedsonmulberryleaves.Thisstagelastsforuptosixweeksuntilthelarvaproducesacocoonofsilkthreadarounditself.Afteraperiodofaboutthreeweeks,theadultmothseventuallyemergefromthesecocoonsandthelifecyclebeginsagain.·Thecocoonsaretherawmaterialusedforthepr
8、oductionofsilkcloth.Onceselected,theyareboiledinwaterandthethreadscanbeseparatedintheunwindingstage.Eachthreadisbetween300and900metreslong,whichmeanstheycanbetwistedtogether,dyedan
