bbbee be-er be-ro beber beebe beour berbe berob beroe beror berre berru beuer beure bo-bo bobr bobre boero boeur booer boore booru borbo boree borer boro- boroo borou borre borro bouee bouer boure brebu breer breo- brere breu- brobo broer broue brrrr bruer bubbe buber buroo burro burru ebber eboue ebure eeeee eorre erbbe erber erere eroor erore error eubro euro- eurre o-r-b oboro oboue obreb oo-er ooooo oreo- orere orero orobe orobo oroer orube oruro ouoro oure- rebbe reber reere rere- reree rerob reuer ro-ro robbe robbo rober robo- robor robur roero rooer roore rooue rorbu rorer rouer roure rubee ruber rubor ruere uber- ubobo uouee ureo- uroob urour urubu uuuuu