-aaa- aabaa aabba aabra aarau abaab ababa ababu abara abaru abbar abbou abbur aboab abobo abora abrar abura aburr ar-ab arab- araba arabo arara araru arbab arbar arbor aroab aroar aroba aroor arora arrau arrou arrua aruaa aruba arura aruru aurar auro- auroa auror aurra babar babau baboo babou babra babur baoro baraa barab barao barar barba barbu baro- baroa baroo baror barra barro barru barua baubo baura bauru bo-bo boaro bobar bobr booba boora booru borau borba borbo boro- boroa boroo borou borra borro bouar bouba boura brobo brora brrar brrrr bubba buraa burao buroo burra burro burru o-r-b oaror obaba obara obora oboro obrab ooooo oraba orara orobo oroua oruro ouara ouoro ourba ra-ra raaba raaor rabab rabba rabor rabou ro-ro robab robar robbo robo- robor robur rooba rorbu rorra rouba roura rubab rubba rubor rubra uaroo ubobo uraba urbar uroob urour urrao urubu uuuuu