[英语考试]职称英语理工类b级

《[英语考试]职称英语理工类b级》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、阅读判断*第十一篇　　ComputerMouseThebasiccomputermouseisanamazinglycleverinventionwitharelativelysimpledesignthatallowsustopointatthingsonthecomputeranditisveryproductive.Thinkofallthethingsyoucandowithamouselikeselectingtextforcopyingandpasting1，drawing，andevenscrollingonthepagewiththenewermicewithth

2、ewheel.Mostofususethecomputermousedailywithoutstoppingtothink2howitworksuntilitgetsdirtyandwehavetolearnhowtocleanit.Welearntopointatthingsbeforewelearntospeak，sothemouseisaverynaturalpointingdevice.Qthercomputerpointingdevicesincludelightpens，graphicstabletsandtouchscreens，butthemouseisstill

3、ourworkhorse.Thecomputermousewasinventedin1964byDouglasEnglehartofStanfordUniversity.Ascomputerscreensbecamemorepopularandarrowkeyswereusedtomovearoundabodyoftext，itbecameclearthatapointingdevicethatallowedeasiermotionthroughthetextandevenselectionoftextwouldbeveryuseful.Theintroductionofthem

4、ouse，withtheAppleLisacomputerin1983，reallystartedthecomputerpublicontheroadtorelyingonthemouseforroutinecomputertasks.3Howdoesthemousework?Wehavetostartatthebottom，sothinkupsidedownfornow.Itallstartswiththemouseball.Asthemouseballinthebottomofthemouserollsoverthemousepad，itpressesagainstandtu

5、rnstwoshafts.Theshaftsareconnectedtowheelswithseveralsmallholesinthem.Thewheelshaveapairofsmallelectroniclight-emittingdevicescalledlight-emittingdiodes(LED)mountedoneitherside4.OneLEDsendsalightbeamtotheLEDontheotherside.Asthewheelsspinandaholerotatesby，thelightbeamgetsthroughtotheLEDontheot

6、herside.Butamomentlaterthelightbeamisblockeduntilthenextholeisinplace.TheLEDdetectsachangingpatternoflight，convertsthepatternintoanelectronicsignal，andsendsthesignaltothecomputerthroughwiresinacablethatgoesoutofthemousebody.Thiscableisthetailthathelpsgivethemouseitsname.Thecomputerinterpretst

7、hesignaltotellitwheretopositionthecursoronthecomputerscreen.Sofarwehaveonlydiscussedthebasiccomputermousethatmostofyouprobablyhaveorhaveused.5Oneproblemwiththisdesignisthatthemousegetsdirtyastheballrollsoverthesurfaceandpicksupdirt.Eventually