-tree bbbee be-er beber beebe beete beeut begee beget begge begue begur begut beppe beppu berbe bereg beret berge berre berru berte betee beter betre bett- bette beuer beure beute brebu breer breet breg- brege bregg brere brett breu- brrrr bruer bruet bruge brugg brute btr-t bubbe buber buger bugge bugre buret burge burgu burru burte burtt burut buter butte butut ebber ebbet eberg ebert ebure eeeee eepee egger egret epptb epure erbbe erber erege erept erere errtu erte erter ertug erupt etete etree etter eturu eurre gberg gberu gbpee geber gebet gebre gebur geere geert geete geeup gegge gerbe gerre gertt getee geter gette getup grebe greer greet grege gregg grepe grete grett greup greut grgur grrrr grubb grube grure gruut gtube gubbe guber gubru guere gurge gurre gurur gutte p-rep pebre peebu peege peere peert peete pepee peppe pept- pepup perer peret perge perre perte perur petbe peter petr- petre petru pette petur peure pgrep prepg prete prute pter- ptere ptprb ptpre ptprg ptprr ptprt ptpru puber puett puget pupet puppe puree purer purge purre purte puter putre putt- putte puttu putup re-up rebbe rebeg reber rebet rebut reege reepe reere reger reget regge regtt regur regut repeg repet reppe reprt repub reput rere- reree reret retee reter retrg rette reuer reuet reute rubee ruber rubup ruegg ruere ruete ruger ruget rugge rupee ruper ruter rutte ruutu tbtbt tbutt teber tebet teege teepe teeup tegre tegur tepee tepet tepeu teppu teret tereu terge tergu terre tert- teter tetr- tette teuge treer treet treg- trepp trept trere trete trett treut trubu truer trugg trupt trute ttttt tuber tupee turbe turbt turet turre turtu turup turut tutee tutte tuuru uber- ugrug upeet upper upput upter urger urgut urter urubu urupe urutu uter- utter uttur utube uturu uuuuu