～間の境界線: boundary line between aとbの境界で: at the boundary of A and B aとbの境界に: at the boundary of A and B ～間の境界線を成す: constitute a boundary line between aとbとの間に横たわる境界線をたどる: track the boundary between 州の境界線: state line〈米〉 郡の境界線: county line ab間の境界線を決める: determine the borderline between A & B ab間の境界線を決定する: determine the borderline between A & B ～間の境界線を撤廃する: break down the boundary between ～間の境界線上にある: lie on the dividing line between aとbの接する境界線: line of meeting of A and B aとb境界線があいまいだ。: The boundary is blurred between A and B. 土地の境界線: property line 海上の境界線: sea border
