-tree bbbee be-er bebel beber beebe beeft beele beete beffe belee belef belet bellb belle berbe berel beret berle berre berte betee betel beter betle betre bett- bette bleer bleet bleft blere blete breef breel breer breet brell brere brett brrrr btr-t ebber ebbet ebble ebell eberl ebert eeeee eeler efere efetf effer effet eftel efter eleet elele ellel eller ellet erbbe erber erere erte ertel erter etete etree ettel etter ettle febel feble febre feele feere felet felle felte feltt ferel feret ferle ferr- ferre ferte fetel feter fette fleer fleet flere flert flete flett freel freer freet frere frett ft-lb ftlee ftrtt lebel leber lebet leell leere leert leffe leftb lelle lerer letbe letre lette rebbe rebel reber rebet reefe reeft reere refel refer refet reffe relee relet relte rere- reree reret retee retel reter rette tbtbt teber tebet teele teell tefe tele- teler tell- telle teret terre tert- tetel teter tetle tetr- tette tlell tlett tllbr treer treet trefe treff trele trere trete trett ttttt