-tree bbbee be-er beber becue becut beebe beete beeut berbe bercu berec beret berre berru berte betee beter betre bett- bette beuer beure beute brebu brece breer breet brere brett breu- brrrr bruce bruer bruet brute btc-e btr-t bubbe buber bucet bucur burcu buret burru burte burtt buruc burut butec buter butte butut c-tec ccccc ccett cebec ceber ceere cerbu cerc- cerce cerec cerer ceret cerre certe cette crebe crece creer crete cretu creu- creue cruce cruet crure ctree cttee cubbe cubeb cuber cubub curce curer curet curre cutcu cutee cuter ebber ebbet ebert ebure eeeee erbbe erber erect erere errtu erte erter eruct etete etree etter eturu eucre eurre rebbe rebec reber rebet rebut recce recet rect- recte recue recur recut reece reere rere- reree reret retee reter rette reuer reuet reute rubee ruber rucer ruere ruete rurec ruter rutte ruutu tbtbt tbutt teber tebet tectb terce teret tereu terre tert- teter tetr- tette treer treet trere trete trett treut trubu truce truer trute ttttt tuber tucet tuctu turbe turbt turet turre turtu turut tutee tutte tuuru u-cee uber- urter urubu uruce urucu urutu uter- utter uttur utube uturu uuuuu