-tree b-r-k bbbee be-er bebek beber becke beebe beeke beete beker bekke berbe berck berec berek beret berk- berke berre berte betee beter betke betre bett- bette brece breck breek breer breet breke brere brett brrrr btc-e btr-t c-tec ccccc ccett cebec ceber ceere cerc- cerce cerec cerer ceret cerke cerre certe cette crebe crece creek creer creke crete ctree cttee ebber ebbet ebert ecker eecke eeeee ekker erbbe erber erect erere erkec erte erter eteke etete etree etrek etter k-t-b kebbe kebek keber kecer keere kekec kerek keret kerre ketek keter kette kreek kreke krete rebbe rebec reber rebet recce recet recke rect- recte reece reere rekke rere- reree reret retee reter rette rt-rk tbtbt teber tebet tectb teket tekke terce terek teret terre tert- teter tetr- tette treck treer treet trere trete trett ttttt