-tree b-e-d bbbee bd-re be-er bebed beber bedde bedee beder bedet bedub bedue beebe beede beerd beete beeut beppe beppu berbe berde berdu bered beret berre berru berte betee beter betre bett- bette beuer beure beute brebu bredd brede bredt breed breer breet brerd brere brett breu- brrrr brud- brude brued bruer bruet brute btr-d btr-t bubbe buber budde buddu budur burde buret burru burte burtt burud burut buter butte butut ddddd debed deber debet debte debut dedde dedee deder dedur dedut deede deepe deepp deepu deere depbt depue derbe derde dered derpt derre derub derue deter detre dette detur deure deut- drdre dredd drede dreed dreep drepe drere drude drupe dubee duded duder duere duerr duete duett dueup duped duper durbe dured duree durer duret durre durte durtu dutte e-dee ebbed ebber ebbet ebert ebure edder eddre edere edred eeeee eeped eepee eerde epptb epure erbbe erber erdre erdut erede erept erere erred errtu erte erter erupt etete etree etter etude eturu eurre p-rep pebre pedee peebu peedu peere peert peete pepee peppe pept- pepup perde perdu perer peret perre perte perur petbe peter petr- petre petru pette petur peude peure prede prepd prete prude prute pter- ptere ptprb ptprd ptpre ptprr ptprt ptpru puber pudde puder pudur puett pupet puppe pured puree purer purre purte puter putre putt- putte puttu putup re-up rebbe reber rebet rebud rebut redbd redde reder redub redup redur reede reepe reere repet reppe reprt reptd repub reput rerde rere- reree reret reted retee reter rette reuer reuet reute rubee ruber rubup ruder ruede ruere ruete rupee ruper rurde ruter rutte ruutu tbtbt tbutt teber tebet teder teepe teerd teeup tepee tepet tepeu teppu teret tereu terre tert- teter tetr- tette treed treer treet trepp trept trere trete trett treut trubu trude trued truer trupt trute ttttt tubed tuber tuder tudre tudur tupee turbe turbt turet turre turtu turup turut tutee tutte tuuru u-dub uber- udder udept udert upedu upeet upped upper upput upter urdee urter urubu urupe urutu uter- utrdb utter uttur utube uturu uuuuu