资料：It’salmostconsideredsacrilegioustodaytoleaveworkattheendofyourworkdayor(forshame！)onaFridayandsimplynotcheckyourworkemailagainuntilyoureturntheofficeduringnormalworkinghours。 Theconstantneedtocheckemailisthetrade-offthemodernworkforcehasmadefortheabilitytoworkanytime，anywhere，hankstosmartphonesandtabletsthatkeepusalwaysconnected。 Butthreeuniversityresearchershavefoundthatit’snotjustdoingabitofworkafterhoursthatcauseburnout。Thetrueculpritisactuallytheconstantworryingaboutoff-houremail。 Anewstudy。“ExhaustedButUnabletoDisconnect，”byLehighUniversity’sLiubaBelkin，VirginiaTech’sWilliamBeckerandColoradoStateUniversity'sSamanthaConroyshowsthatemployeesaregrowingexhaustedbytheexpectationthattheywillalwaysbeavailable，neverknowingwhatkindofworkrequestswillbeaskedofthemoffhours。 Typically，companiesdon’tmeantostressemployeesoutlikethat。Mostcompaniesdon'thaveformalpoliciesthatsaypeoplemustanswerworkemailsafter-hours，(except，perhaps，incaseswhereanemployeeisoncallduringspecifictimes)。 Butpoliciesandculturetendtobetwodifferentthings。Ifsupervisorsroutinelyemailemployeesafterhoursandexpectafastresponse(oftenbecausetheirsupervisorsaredoingthesametothem)，thenthemessageisclear:wheneverthebossemails，theemployeeisexpectedtobeavailable。 Thesolutionisforbossestotellemployeesthatanafter-hoursemaildoesn’tnecessarilyrequirearesponsebeforethenextworkday，andtoalsosetsometimeswhenafter-hoursemailingisconsideredacceptableandprohibited，suchasnoemailsviathedinnerhour，onweekends，orafter10p.m.，theresearcherssay。 Whythestudysaidpeopleare“ExhaustedButUnabletoDisconnect”？
A.Because they never know what kind of work requests will be asked off hours. B.Because they are required by the company to answer emails off hours. C.Because smart phones and tablets keep us connected all the time. D.None of above.正确答案A
