b-tree bbbbbb beebee beeker beeter bekker berbee berber bereet bereke berere berker berrer berret bertre betere betete bettee better breere brekke brette ebbert eebree erbree errett k-tree kebber keeker kerber kerker kertee ketter kreker kretek r-tree reeker reteer reteet retere retree retret retter t-tree teebee teetee teeter terete terrer terret terter tertre tetete tetter trebek treete treker tretee trette