bbbb bbdd bbdo bd-r bdii bibb bibi bibo bidi bido bidr bidu bio- bioi biou birb bird biri biro birr biru bobb bobi bobo bobu bodb bodi bodo bodu boi- boid boii boiu boob bood boor bor- bord bori boro borr boru boud bour brdo brid brio brob brod broo bror brou brrr brud bubb bubi bubo bubu budb budd budi budo budu buid buir buiu bur- burb burd buri buro burr buru d-bo dddd ddub dibb dibo didi dido didu diii dior diou dird dirr dobb dobi dobu dod- dodd dodi dodo doid doob dood door dord dori doro dorr doru doub doud dour drib drob drod drou drub drui druu dub- dubb dubu dudd dudo dudu duid duir duo- duri duro duru duur ibdo ibid ibrd ibri ibro iddo idid idio idir idro idub iduo iiii iiio iioi iioo iobi iod- iodd iodo ioii ioio iooi iooo iori irdo iri- irid irio irob irod irri iuiu obbo obid oboi obor obri obro odbo oddd oddi odio odir odiu odoo odor odou odur oido oiii oobi oodi ooid oooo oord orbb orbi orbo orbu ordo ordu ori- orid orio oro- oror orri orro orub ouii ouir our- ouro ouu- rbbb rbbr rdio rib- ribo ribu ridd ridi rido riou riri rob- robb robi robo robu rodd rodi rodo roid roio roir roiu roob rood rooi roor rori roro roru roub roud rrrr rubb rubi rubu rudd rudi rudo ruid rurd ruri ruro ruru ruud ubbi ubbo ubid ubii ubir ubod ubud uddi udid udir udoo uirr uor- urbi urdu urib uriu uro- uroo urri urur uuri uuuu