-tree bbbee be-er be-ro bebel beber beblo bebot beebe beele beete beeut belbo belee belet bellb belle bello belot belue belur belut beote beour berbe berel beret berle berlo berob beroe berol beror berre berru berte berto betee betel beter betle betoo betor betou betre bett- bette betto betul beuer beule beure beute bleer bleet blere blete bleue bloor blorb blore blort blote bloto blott bloue blout bluer bluet blurb blure blurr blurt bluto bo-bo bobet boble bobr bobre boeol boero boeur bolbe bolel boleo boler bolet boll- bolle bollo bollu bolte bolto booer boole boore boort booru borbo boree borel borer boret borle boro- boroo borot borou borre borro borul borut botel botet botou botro botte bottu bouee bouel bouer bouet boul- boule boulo boult boure boute bouto brebu breel breer breet brell brelo breo- brere breto brett breu- brobo broer brole broll brolo brool broto broue brout brrrr bruer bruet brule brull brute btr-t bubbe buber buble buell bulb- bull- bulle bulou bulto bulul bulut buolt burel buret burle burol buroo burro burru burte burtt burut buteo buter butle buto- butor butot butou butte butuo butut ebber ebbet ebble ebell ebelo eberl ebert eblul eboue ebull ebure eeeee eeler elbot eleet elele eleo- eleot eleut ellel eller ellet elloe ellul eloee elole eloor elore eloro elote elout elrob eltro elubo elulu eluru elute eorre erbbe erber erere eroor erore eroto errol error errtu erte ertel erter etete etoll etool etoro etour etree ettel etter ettle eturu eubro euell euler eurel euro- eurre lebel leber lebet leell leere leert leleu lelle lerer lerot letbe letot letre lette letto letur leuro lobbe lobbo lober loble lobo- lobor loler lollo lolol loobu looer loore loote lorel loreo lorer loret lorre lorut lotor lotru lotte lotto louer loule loure louro lubbe luber luble lubur luebo lulle lulte lulul lurer lurue lute- luteo luter lutol lutte lutto o-r-b obbet obele obert obete obole obolo oboro obote oboue obout obreb oelet oerel oerle oleo- olere olleo oller ollur olotu olour oltet oltre oo-er ooooo orble orbot orell oreo- orere orero orlet orobe orobo oroer orolu orout orret orter ortet ortoo orube oruro orutu otell otelo otere otero otole otolo ototo otour otter ottur otulu oture oubut ouert oullo ouoro oure- ourol outer outre outro outto rebbe rebel reber rebet rebol rebut reere relee relet rello relot relte relue rere- reree reret rerob retee retel reter retro rette retto reuel reuer reuet reule reute ro-ro robbe robbo rober roble robo- robor robot robrt robte robur roell roero roleo rolle rollo rooer roole roore roote rooue rorbu rorer roteb rotel roter rotle roto- rotol rotor rotot rotte rotto roubt rouer rouet roule roull roure route routt rubee rubel ruber ruble rubor ruele ruell ruere ruete ruler rullo ruter rutle rutte rutul ruule ruutu tbolt tbtbt tbutt teber tebet teele teell tele- teleo teler teleu tell- telle tello telo- teolo teotl teret tereu teror terre terro tert- teruo tetel teter tetle tetr- tetro tette teuto tlell tlett tllbr to-be tobbe tobel tober tobet tobol tobor tobot tobou tobre toerr toeto tolbo toler tolet tolle tollo toloo tolor tolu- toobe toole toolt toore torbe torel toreo toret torob torre torro torte torto tortu torue torul totel toter totle toto- totoe totoo totte touel toule toull toure touro toute treer treet trele trere trete trett treut troee troll trott troue troul trout trubu truel truer trule trull truro trute ttttt tuber tubo- tubou tubul tuell tuelt tuero tulet tulle tulor tulou tuotu turbe turbo turbt turel turet turle turot turre turro turtu turul turut tutee tutel tuteo tutle tutor tutte tutto tuuru ubble uber- ubobo ubolt ullet ullur ulteo ultre ululu uluru uouee urelu ureo- uroob urour urtel urter urtlu urubu urutu utebo uter- utero utole utro- utror utter uttur utube uturu ututo uuuuu