-tree bbbee be-er be-ro beber bebot beebe beeft beete beffe befoe befor beofe beoff beote berbe beret berob beroe beror berre berte berto betee beter betoo betor betre bett- bette betto bo-bo bobet bobr bobre boero bofet boffo booer boore boort borbo boree borer boret boro- boroo borot borre borro botet botro botte breef breer breet breo- brere breto brett brobo broer broft broto brrrr btr-t ebber ebbet ebert eeeee efere efetf effer effet efore efter eofor eorre erbbe erber erere eroor erore eroto error erte erter etete etoro etree etter febre feeor feere fefor feoff feret ferr- ferre ferro ferte feter feto- fetor fette foore foote fore- foreo foret forro forte forto fotte freer freet frere frett frobe froot frore frote ftrtt o-fer o-r-b obbet obert obete oboro obote obreb offer offof offre offto ofoto ofter oo-er ooooo orbot oreo- orere orero orfeo orfoe orfor orobe orobo oroer orret orter ortet ortoo otere otero ototo otter rebbe reber rebet reefe reeft reere refer refet reffe reffo rere- reree reret rerob retee reter retro rette retto ro-ro robbe robbo rober robo- robor robot robrt robte roero roffe rofor rooer roofe rooft roore roote rorer roteb roter roto- rotor rotot rotte rotto tbtbt teber tebet tefe teret teror terre terro tert- teter tetr- tetro tette to-be tobbe tober tobet tobor tobot tobre toeof toerr toeto tofet toffo tofor tofte toobe toore torbe toreo toret torob torre torro torte torto toter toto- totoe totoo totte treer treet trefe treff trere trete trett troee trofe troff troft trott ttttt