-tree b-r-k bbbee bbser be-er bebek beber bebes beebe beebs beeke beers beest beete beets beker bekes bekke berbe berek beres beret berk- berke berks berre berse berte berts besee beset besse beste bests betee beter betes betke betre betrs bett- bette betts breek breer brees breet breke brere brers brese bress brest brets brett brrrr bskts btr-t ebber ebbet ebers ebert eeeee ekers ekker erbbe erber erebs erere eresk erest erets erres erses erste ersts erte erter ertes esere esker esser esses essse estee ester estes estet estre eteke etest etete etree etrek etres etter ettes k-set k-t-b kebbe kebek keber keeks keere keest keets kerbs kerek keres keret kerre kerrs kerse kerss keser kesse keste ketek keter kette krebs kreek krees kreke kresk kress krest krete rebbe reber rebet rebts reeks reere reese reesk reest rekke rere- reree reres reret resee reses reset reske resse reste restr rests retee reter retes rette retts rt-rk sebbe sebek sebes sebet seebe seeke seeks seere seers seese seest seete seker sekes sekke serbs serer seres seret serke serre serse serss sert- serte serts seser seses sesse seste setee seter setse sette setts skeer skees skeet skere skers skete skrte sssrb sssss steek steer stees steet steke stere sterk sterr sters stert stete stets stker strbe streb stree strek stret strrs tbtbt teber tebet teebs teers teese teest teets tekes teket tekke terek teres teret terre terrs terse tersk tert- tesse teste tests teter tetes tetr- tette treer trees treet treks trere tres- trese tress trest trete trets trett trsek tsebe tsere tsets ttest ttttt