Joannehadplannedtoleaveworkearlythisafternoonatthreeo'clock.Butwhenshefinallycameoutofherofficealltheotherconductorshadalreadyleft.NowshewascaughtinaheavytrafficincentralBirmin

　　Joannehadplannedtoleaveworkearlythisafternoonatthreeo'clock.Butwhenshefinallycameoutofherofficealltheotherconductorshadalreadyleft.NowshewascaughtinaheavytrafficincentralBirminghamat5:30andat6:30shewasexpectedtobeatameeting．

　　Atlastshearrivedatherhome．AssheopenedthedoorshenoticedsomethingunusualaboutShebaalargedog．ShecouldseeeasilyShebawasfeelingbadandcouldhardlybreathe（呼吸）.Joanneknewshewouldhavetotakeherdogtothevetimmediately.

　　“Itlookslikethere'ssomethinginherthroat（喉咙）”saidDr.Stem“Itshouldn'ttakemetoolongtogetitout.”

　　BeinginahurryJoanneleftthedoctorwiththedogandrushedbackhome．Assheoncemoreenteredthehousethephonerang．Dr.Stern'sloudandworriedvoicewasheard“Iwantyoutogetrightoutofthathouseimmediately.Thepolicewillbethereanytimenow.Waitoutsideforus.”Joannewassurprisedandafraid．Shequicklyranintothestreet.

　　Atthatmomentapolicecarstoppedoutsidethehouse．Twopolicemengotoutandranintothehousethroughthestillopendoor.Thenthedoctorarrived．Justthenthetwopolicemenreappearedfromthehousehalf-carryingawhite-facedmanwhoitseemedcouldhardlywalk.Therewasblood（血）alloverhim.

　　“Ithinkhemustbeathief”saidthedoctor.“IknewhewastherebecausewhenIfinallyremovedwhatwasinSheba'sthroatandfounditwasthreehumanfingers.”

　　(1)WheredoesJoanneprobablywork?

　　[]

　　A．Atabusortrainstation.

　　B．Inananimalhospital.

　　C．inapolicestation.

　　D．Itisn'tmentioned.