Americaiswell-knownforitsequality,liberty,fraternity.Everyoneisveryfriendlyandinformal.Childrenoftencalltheirparentsbytheirfirstnamesandatwork.Subordinatesdonotnormallyuse"Mister"whenaddressingtheirsupervisors.Tothosevisitorswhocomefromamorerigidandstratifiedsociety,suchcasualnesscanbeconfusing,leadingtoegregious（严重的）blunders.Conversely,manyworldly,sophisticatedAmericansappearmortifiedbecausetheyfeelAmericaisnot"civilized,"withacapital"C."However,weknowofterriblyembarrassingincidentsfrommistakeswhichonlyaninnocentforeignerwouldhavemade. 　　Publicdisplaysofaffectionbetweenthesexesareverycommon,unlikeperhapswhereyouhavecomefrom.Inmanycities,especiallySanFrancisco,homosexualityisanacceptedwayoflife.Youmaythereforeseemenbeingaffectionatewithmenandwomenwithwomen.Ifyoudisapproveofhomosexualsbecauseofyourreligiousorculturalbeliefs,pleasekeepittoyourself.Youmightevenfindyourselfaguestinagayperson'shome-andmightbecomeshockedtorealizethatyourhostisanormalhumanbeinglikeanyotherandthatyouareactuallyenjoyinghishospitality.Manycouplesalsolivetogetherwithoutbeingmarried-andmaynevermarry.Butyoumustrealizetheirbondisprobablyasstrongasthebondofmarriage.Sodon'tthinkoneofthemisavailablefora"date." 　　Americaisanotoriously"open"society,andtomostforeignersAmericansoftenappearexceptionallyand"instantly"friendly.Butsometimessuchopennesscanleadtoseriousmisunderstanding,especiallybetweenmenandwomen.Acasualinvitationtohavedrinksand/ordinnerdoesnotmeanthatyourAmericanhostalsowantstobecome"intimate"withyouafterwards.Sobecarefulnottoreadtoomuchintoafriendlyinvitation.