DOUBLETON

be bo de do ed el en et lo ne no nu od oe on to un ut

bed bel ben bet bod boo bot bud bun but deb del den doe dol don dot dub due dun duo eld end eon led let leu lob loo lot neb net nob nod noo not nub nut obe ode old ole one ono oot oud out ted tel ten tod toe ton too tub tun udo ute

bedu belt bend bent bled blet blot blue bode bold bole bolo bolt bond bone boon boot bout bund bunt bute debt delt dent dole dolt done dote duel duet dune dunt ebon enol lend leno lent leud lobe lobo lode lone loon loot loud lout lube lude lune lunt lute node noel nolo note nude oboe obol oleo onto tend toed told tole tolu tone tool toon tube tule tune udon unbe unde undo unto