英语专八阅读训练题2017英语专八阅读训练题语考试的过程中除了掌握一定的知识积累外，还需要掌握一些必要的.做题技巧，这有利于我们提高做题效率。以下是小编为大家搜索整理的2017英语专八阅读训练题，更多精彩内容请及时关注我们应届毕业生考试网!FingerprintsThesearchforlatentprintsisdoneinasystematicandintelligentmanner.Investigatorsdeveloptechniquestolocatetracesoffingerprintsatacrimescene.Thebasicpremiseinsearchingforlatentprintsistoexaminemorecarefullythoseareas,whichwouldmostlikelybetouchedbypersonswhohavebeenonthescene.Thenaturalmannerinwhichapersonwoulduseandplacehishandsinmakinganentranceorexitfromabuildingorinhandlinganyobjectisthekeytothediscoveryoflatentprints.Whereaforcedentrancehasbeenmade,latentprintsarelikelytobefoundonanysurfaceadjacenttooratthatpoint.Anyobjectwithasmooth,non-poroussurfaceislikelytoretainlatentprintsiftouched.Fingerprintsonroughsurfacesareusuallyoflittlevalue.Ifthefingermarkdoesnotdiscloseridgedetailwhenviewedunderareadingglass,thechancesarethatitsvalueinidentificationisnilwhenphotographed.Wherefingermarksarefound,itwillbenecessaryfortheinvestigatortocomparethemagainsttheonesofpersonshavinglegitimateaccesstothepremisessothatthetracesmightbeeliminatedashavingevidentiaryvalueiftheyprovetobefromthesepersons.Placestosearchforprintsonanautomobilearetherearviewmirror,steeringwheelhub,steeringcolumn,windshielddashboardandthelike.Dustingofsurfacemaybedonewithafinebrushorwithanatomizer.Thewhitpowdersusedarebasicallyfinelypowderedwhitelead,talc,orchalk.AnotherlightpowderisbasicallyChemist’sgray.Agoodblackpowderiscomposedoflampblack,graphite,andpowderedacacia.Dragon’sbloodisgoodpowderforwhitesurfaceandcanbefixedonpaperbyheating.Indevelopinglatentprints,theacceptedmethodistousethepowdersparinglyandbrushlightly.Donotusepowderifthefingermarkisvisibleunderobliquelighting.Itcanbephotographed.Agoodpolicyforthenoviceistoexperimentwithhisownprintsonasurfacesimilartotheonehewishestosearchinordertodeterminethepowderbestsuitedtothesurface.Fingerprintsafterdustingmaybeliftedbyusingfreshcellulosetapeorcommerciallypreparedmaterialespeciallydesignedtoliftandtransfe