题目内容：
RobertEdwardswasblindedinatrafficaccident.Hewasalsoalittledeaf_51_oldage.Lastweek,hewastakingawalknearhishomewhenathunderstormcame.Hehid_52_thestormunderabigtreeandwasstruckbylightning.Hewasknocked_53_thegroundandwokeupsome20minutes_54_,lyingfacedowninwaterinwaterbelowatree.Hewentintothehouseandlaydowninbed.Ashorttimelater,heawoke;hislegsfelt_55_andhewastrembling,but,whenheopenedhiseyes,hecouldseetheclockacrosstheroomfadinginandoutinfrontofhim.Whenhiswifeentered,he_56_herforthefirsttimeinnineyears.Doctors_57_thathehadregainedhissightandhearingobviouslyfromtheflashoflightning,buttheywereunabletoexplainthat.Theonly_58_explanationofferedbyonedoctorwasthat,_59_Edwardslosthissightasaresultoftraumainaterribleaccident,perhapstheonlywayitcouldberestoredwasby_60_trauma.__________
A.because
B.becauseof
C.as
D.since
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