b-tree bbbbbb bebeto beebee beefer beeter before befree befret berbee berbeo berber bereet bereft berere berrer berret bertre betere betete bettee better bettor bobber bobete bobote boeber boerre bofete boffet boober booboo bootee booter borbor boreto borfee borore bororo borte botere botero botete botoro botree botter breefe breere breffo brette broter brotto ebbert eebree effere effete effoff effore effort efreet efter- eototo erbree eroto- errett etoeot ettore feeror feetof feofor ferber ferfer ferrer ferret ferro- fertee ferter fetter foboff foerre foeto- foetor foofoo footer forrer forrot fortee forter frbroo freebo freeof freeto frefre frette frobot froofe fterer fterre o-bofe oberto obtree oerter oferre offeet oftfor oofotr oooooo ottoor r-tree reboot rebore rebote reefer reeffe refeet refeff refert refete refoot refret refter rerobe reroof reroot reteer reteet reteoo retere retore retort retree retret retro- retrot retter robber robert roboto roofer rooter rootof rootte rorter rotter t-tree teebee teeoff teetee teeter terete terreo terrer terret terror terrot terter tertre tetete tetter to-fro tobeor toboot toetoe toffee tofore toofer tooter tootoo torero torfer tororo torret tortor totebo totoro totrot totter trebor treeof treete trefet trefor trefot trefte tretee trette troffe trotro trotte