_________(53)A.Since B.Out C.From D.Through

The situation is rather complicated ______ we have two managing directors.A．since thatB．in

He cannot be tired _______ he has walked only half a mile. A：since B：whether C：when

He s lived in London______.A．since a long timeB．for some timeC．long beforeD．some time ago

___________[A] Since [B] If [C] Unless [D] While

_________(52)A.towards B.againstC.upon D.through

_________(53)A.since B.whereC.though D.when