b-tree bbbbbb becker becket becure beebee beeker beeter bekker berbee berber bercke bereet bereke berere berker berkut berrer berret bertre berube betere betete betrue bettee better betutu beurre breere brekke bretcu brette breuer brubru bruker bruket bruree bubber bububu bucker bucket bukett bukkur bukuru burbet burbur burcer burket burkut burree burrer burret buruku burutu butere butter butucu c-cube ceecee cerete ceruce creeke creete creket cubber cubeck cubert cubube cucube cucurb curber curete currer curret curter cutcut cuttee cutter ebbert eburru eckert eebree eerect erbree erketu errett etcetc ettutu eutere k-tree kebber keeker kekkut kerber kereru kerker kerkuk kertee ketter ketuke keuruu kreker kretek krueck kubeer kukere kurkcu kurree kururu kutke kutter r-tree rebbec rebeck rebeuc rebuck rebuke rebute recrue recuer recurb recure recurt reeker rekrut retece reteer reteet retere retree retret retter rettur retube returu reubke reuere reuter reutte rubbee rubber rubutu rucker rukutu rurkee rurutu ruttee rutter rutube t-tree t-tube teebee teetee teeter teeuck tekrur tercer tercet terete terrer terret terter tertre tetete tetter teucer tr-rec trebce trebek trebur treck- treece treete treker tretee trette tretuk treuce truett truker tubber tucker tucket tuktuk turbet tureck turker turret turtuk turtur turucu tururu tuteur tutter tuttut u-tube uecker ureter urette uteute utukku utukur