bbbb bbdd bbdo bbfn bd-r bduf bnor bnrr bobb bobo bobu bodb bodo bodu bofd boff bofu bond bonn bono bonu boob bood boof boon boor bor- bord borf born boro borr boru boud bouf boun bour brdo brfu brno brob brod bron broo bror brou brrr brud brun bubb bubo bubu budb budd budo budu buff bufo bufr bunb bund bunn buno bunu buon bur- burb burd burn buro burr buru d-bo dbfo dbrn dddd ddub dfrf dobb dobu dod- dodd dodo doff dond donn dono donr doob dood doof doon door dord dorf dorn doro dorr doru doub doud douf doun dour drno drob drod drof dron drou drub druu dub- dubb dubu dudd dudo dudu duff dufu dunn duno duo- duon durn duro duru duur ffff ffrr ffun fndd fndn fndr fnuf fofo fond fono food foof foon for- forb ford forn foro forr foud foun four frob fron frou frub frun fubb fubu fudd fuff fufu fund funf fuor fur- furn furo furr nbbo nbuf nddb nddo ndor ndrf nfff nfon nndb nnnn nobo nobu nodo nodu non- nonn nono nonu noo- noob noon nooo noor nor- norb nord norf norn noro norr noun nour nron nrrd nudd nudo nuff nunn nuno nuon nurd nurn nurr nuru obbo obon obor obro odbo oddd odnb odon odoo odor odou odur ofdr off- offo offr offu ofno ofor ondo onno onod onon onor onur ooff oooo oord orbb orbo orbu ordn ordo ordu orff orfu orno oro- orof oron oror orro orub ouff oun- ound our- ourn ouro ouu- rbbb rbbr rnbr rndf rnod rob- robb robo robu rodd rodo roff rofo rond rono roob rood roof roon roor roro roru roub roud rouf roun rrrr rrun rubb rubu rudd rudo ruff rufo rund runf runn runo rurd ruro ruru ruud ruun ubbo ubod ubon ubud udon udoo udun unbd undo unfd unno unon unrf unro uofo uor- urdu urff uro- uroo urun urur uuno uuuu