Whilelearningthesciencelessons,Iusedtogetadoubt--whyear,nose,tongueandeyesshouldbecalledasspecialsenses?Thebasicreasonisthatthesearethechannelsthroughwhichwemaintaincontactwiththesurroundings.Thoughapparentlyitmayfeelliketheseareindividualsensoryorgans,theydoshowsomeconnectivity.Interestingly,ourhearingislesssharpafterweeataheavyfood.Isn’titgoodforasoundnapafterastomach-fullmeal?Thatdoesnotmeanwegodeafafterameal,butthehearingpitch(强度)doeschangeafteraheavymeal. Weusuallygivecreditofthetastetoourtongue,butdoyouknowthatunlesssaliva(唾液)dissolvessomething,ourtonguecannotrecognizethetasteofthefoodeaten.Tasteisnothingbutthefoodchemicalsdissolvedinthesalivabeingsensedbythetastebuds(味蕾)presentonthetongue.Trytodryoffyourtongueandmouthwithatissuepaperandthentastesomething. Womenaremuchbettersmellersthanmen.Theyarebornwiththischaracteristicabilityandcancorrectlyrecognizetheexactfragranceofthesample.Weallcanstorealmost50,000differentsmells,whicharestronglytiedtothememories. Pupils(瞳孔)donotrespondtolightalone,buttotheslightestbitofnoisearoundtoo.Thussurgeons,watchmakersandthoseprofessionalswhohavetoperformamuchdelicatejobdoprefertohaveasound-freeenvironment.Evenasmallnoisecanenlargetheirpupils,changethefocusandmaketheirvisionlessclear. Eachandeveryoneofushasaparticularorindividualisticorcharacteristicsmell,whichisuniquetous,exceptthetwins.Thissmellisverysubtleyetcanbesensedevenbyanewborn.Itmaybeduetothissmellthatthenewbornrecognizesthepresenceofhisparentsaround. 小题1:Whatmayhappenafteryouhavehadarichlunch?
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