材料全屏

材料全屏

                                                                         ComputerMouse

【*】Thebasiccomputermouseisanamazinglycleverinventionwitharelativelysimpledesignthatallowsustopointatthingsonthecomputeranditisveryproductive.Thinkofallthethingsyoucandowithamouselikeselectingtextforcopyingandpasting,drawing,andevenscrollingonthepagewiththenewermicewiththewheel.Mostofususethecomputermousedailywithoutstoppingtothinkhowitworksuntilitgetsdirtyandwehavetolearnhowtocleanit.Welearntopointatthingbeforewelearntospeak,sothemouseisaverynaturalpointingdevice.Othercomputerpointingdevicesincludelightpens,graphicstable tsandtouchscreen,butthemousestillourworkhorse.
【*】Thecomputermousewasinventedin1964byDouglasEnglehartofStanfordUniversity.Ascomputerscreensbecamepopularandarrowkeyswereusedtomovearoundabodyoftext,itbecameclearthatapointingdevicethatallowedeasiermotionthroughthetextandevenselectionoftextwouldbeveryuseful.Theintr oductionofthemouse,withtheAppleLisacomputerin1983,reallystartedthecomputerpublicontheroadtorelyingonthemouseforroutinecomputertasks.
【*】Howdoesthemousework?Wehavetostartatthebottom,sothinkupsidedownfornow.Itallstartswithmouseball.Asthemouseballinthebottomofthemouserollsoverthemousepad,itpressesagainstandturnstwoshafts.Theshaftsareconnectedtowheelswithseveralsmallholesinthem.Thewheelshaveapairofsmallelectr oniclight-emittingdevicescalledlightemittingdiodes(LED)mountedoneitherside.OneLEDsendsalightbeamtotheLEDontheotherside.Asthewheelsspinandaholerotatesby,thelightbeamgetthroughtotheLEDontheotherside.Butamomentlaterthelightbeamisblockeduntilthenextholeisinplace.TheLEDdetectsachangingpatternoflight,convertsthepatternintoanelectr onicsignal,andsendsthesignaltothecomputerthroughwiresinacablethatgoesoutthemousebody.Thiscableisthetailthathelpsgivethemouseitsname.Thecomputerinterpretsthesignaltotellitwheretopositionthecursoronthecomputerscreen.
【*】Sofarwehaveonlydiscussedthebasiccomputermousethatmostofyouprobablyhaveorhaveused.Oneproblemwiththisdesignisthatthemousegetsdirtyastheballrollsoverthesurfaceandpicksupthedirt.Eventuallyyouhavetocleanyourmouse.Theneweropticalmiceavoidthisproblembyhavingnomovingparts.
1

【单选】

Mostcomputeruserswanttoknowhowthecomputermouseworks.（）

A

True

B

False

C

NotGiven

答案及解析：题干句的意思是大多数计算机使用者都想了解鼠标的工作原理。利用特征词most和关键从句howthecomputermouseworks作为线索,在文中找到相关句“Mostofususethecomputermousedailywithoutstoppingtothinkhowitworksuntil”,意为大多数电脑使用者天天用电脑鼠标却没有想去了解鼠标的工作原理。由此可见题干句的内容与原文不一致,因此不是正确信息。