bo-bo bobr bombo boomb boort booru borbo bormo boro- borom boroo borot borou borro borum borut botom botou botro bottu bouto brmmm brobo brom- bromo broom broto brout brrrr brumm btr-t bumbo bumbu buroo burro burru burtt burut buto- butor butot butou butuo butut mboro mburu mmmmm mobor mobot mobro mombo mombu momot mooro mooto morbo mormo moror morou morro morum morut moto- motor motru motto mottu mrmom mrorr mt-tm mt-tr mt-tt mtoto mumbo mummu murom muror murot murro murru murum murut muto- mutum mutuo muuto o-r-b oboro obout obrom omoro omoto omout ooooo orbom orbot ormur orobo oromo orout orrum ortoo oruro orutu otomo ototo otour ottom ottur oubut ouoro outro outto rmutt ro-ro robbo robo- robor robot robrt robur roomu rorbu roto- rotor rotot rotto roubt roumm routt rubor rumbo rummo rummu rumor ruomu ruutu tbtbt tbutt tobor tobot tobou tombo tombu tommo tomo- tomom tomor torob torro torto tortu toto- totoo totum touro tromm trott troum trout trubu truro ttttt tu-mo tubo- tubou tumbo tumbu tummo tumor tumut tuomo tuotu turbo turbt turot turro turtu turut tutor tutto tuuru ubobo umbro umour uroob urour urubu urutu utro- utror utrum uttur uturu ututo uuuuu