Think of gloves, scissors, indeed anything which needs its opposite in order to be greater than it can be alone (as anyone who has lost a glove will know!).
аўторак, каўбой, аўгур, Аўстрыя, Аўдоцця, Аўрора, Каўказ, Боўш, Роўда, аўгіевы стайні;