-tree bbbee be-er be-ro beber bebot becco beebe beete beote berbe berec beret berob beroe beror berre berte berto betee beter betoo betor betre bett- bette betto bo-bo bobet boboc bobr bobre bocce bocet bocor boece boero booce booco booer boore boort borbo borce borec boree borer boret boro- boroo borot borre borro botet botro botte brece breer breet breo- breoc brere breto brett brobo broce broer broto brrrr btc-e btr-t c-cor c-tec ccccc ccett cebec ceber ceco- ceere ceoce ceoor cerc- cerce cerco cerec cerer ceret cero- ceroc cerre cerro certe ceto- cette co-bo co-co cobbe cobot cobre cocc- cocce cocco coceo cocto coete cooee cooer coore coote corbe corbo corce core- coree corer coro- corot corre corte corto coter cott- cotte cotto crebe crece creer creo- creot crete croce croco crooe croot crore crote crott ctree cttee ebber ebbet ebert ecto- ector ectot eeeee eorre erbbe erber erect erere eroor erore eroto error erte erter etete etoro etree etter o-r-b obbet obert obete oboro obote obreb ocoee ocote ocr-b ocree octet octo- octor oeco- oo-er oocre ooooo orbec orbot orcet oreco oreo- orere orero orobe orobo oroco oroer orret orter ortet ortoo otcbb otere otero otoce ototo otter r-co- rebbe rebec reber rebet recce recco recet rect- recte recto reece reere rere- reree reret rerob retee reter retro rette retto ro-ro robbe robbo robec rober robo- robor robot robrt robte rocco rocor roero rooer roore roote rorer roteb roter roto- rotor rotot rotte rotto tbtbt tcobb teber tebet tectb teoco terce terco teret teror terre terro tert- teter tetr- tetro tette to-be tobbe tober tobet tobor tobot tobre tocco toco- toece toerr toeto toobe toore torbe torce toreo toret torob torre torro torte torto toter toto- totoe totoo totte trboc treco treer treet trere trete trett troco troee trott ttttt