-tree bbbee be-er bebel beber beebe beele beete beeut begee beget begge begle begue begur begut belee beleg belet belge bellb belle belue belur belut berbe bereg berel beret berge berle berre berru berte betee betel beter betle betre bett- bette betul beuer beule beure beute bleer bleet blere blete bleue bluer bluet blurb blure blurr blurt brebu breel breer breet breg- brege bregg brell brere brett breu- brrrr bruer bruet bruge brugg brule brull brute btr-t bubbe buber buble buell buger bugge bugle bugre bulb- bulge bull- bulle bulul bulut burel buret burge burgu burle burru burte burtt burut buter butle butte butut ebber ebbet ebble ebell eberg eberl ebert eblul ebull ebure eeeee eeler egger egret eleet elegu elele eleut elge elgee elger ellel eller ellet ellul elulu eluru elute erbbe erber erege erere errtu erte ertel erter ertug etete etree ettel etter ettle eturu euell euler eurel eurre gberg gberu gebel geber gebet gebre gebur geere geert geete gegge gelee geler gelle gelru gelug gerbe gerle gerre gertt getee geter gette ggulu glebe gleer gleet glegg glele glere glete glett glubb gluer glut- glute glutt grebe greer greet grege gregg grell grete gretl grett greut grgur grrrl grrrr grubb grube gruel grure gruut gtube gubbe guber gubru guell guelt guere gugel gugul guler gulet gulle gulte gurge gurle gurlt gurre gurur gutte lebel leber lebet leell leere leert leger legge leleu lelle lerer lerge letbe letre lette letur leuge llerg lubbe luber luble lubur luger lugge lugre lulle lulte lulul lurer lurgg lurue lute- luter lutte rebbe rebeg rebel reber rebet rebut reege reere regel reger reget regge regle regtl regtt regul regur regut relee relet relte relue rere- reree reret retee retel reter retrg rette reuel reuer reuet reule reute rubee rubel ruber ruble ruegg ruele ruell ruere ruete ruger ruget rugge ruler ruter rutle rutte rutul ruule ruutu tbtbt tbutt teber tebet teege teele teell tegel tegre tegur tele- teleg teler teleu tell- telle teret tereu terge tergu terre tert- tetel teter tetle tetr- tette teuge tlell tlett tllbr treer treet treg- trele trere trete trett treut trubu truel truer trugg trule trull trute ttttt tuber tubul tuell tuelt tulet tulle turbe turbt turel turet turle turre turtu turul turut tutee tutel tutle tutte tuuru ubble uber- uggle ugrug ulger ullet ullur ultre ululu uluru urelu urgel urger urgut urtel urter urtlu urubu urutu uter- utter uttur utube uturu uuuuu