-tree b-e-d bbbee bd-re be-er bebed beber bedde bedee beder bedet bedub bedue beebe beede beerd beete beeut 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 deere derbe derde dered derre derub derue deter detre dette detur deure deut- drdre dredd drede dreed drere drude dubee duded duder duere duerr duete duett durbe dured duree durer duret durre durte durtu dutte e-dee ebbed ebber ebbet ebert ebure edder eddre edere edred eeeee eerde erbbe erber erdre erdut erede erere erred errtu erte erter etete etree etter etude eturu eurre rebbe reber rebet rebud rebut redbd redde reder redub redur reede reere rerde rere- reree reret reted retee reter rette reuer reuet reute rubee ruber ruder ruede ruere ruete rurde ruter rutte ruutu tbtbt tbutt teber tebet teder teerd teret tereu terre tert- teter tetr- tette treed treer treet trere trete trett treut trubu trude trued truer trute ttttt tubed tuber tuder tudre tudur turbe turbt turet turre turtu turut tutee tutte tuuru u-dub uber- udder udert urdee urter urubu urutu uter- utrdb utter uttur utube uturu uuuuu