bbbb bnor bnrr bobb bobo bobu bomb bomu bonn bono bonu boob boom boon boor bor- borm born boro borr boru boum boun bour brno brob brom bron broo bror brou brrm brrr brum brun bubb bubo bubu bum- bumb bunb bunn buno bunu buon bur- burb burm burn buro burr buru mbou mmmm mmor mmun mnbb mobb mobo momo momu mon- monn mono monu moob moon moor morb morn moro moru moun mour mrbb mrbm mron mubo mumm mumo mumu munn muno munu muon murn muro murr muru nbbo nmon nnnn nobm nobo nobu nom- nomo nomu non- nonn nono nonu noo- noob noon nooo noor nor- norb norm norn noro norr noun nour nron numb numm numu nunn nuno nuon nurn nurr nuru obbo obon obor obro ombo ombu omn- omo- omon omoo omor omro omuo onno onon onor onur oooo orbb orbo orbu ormn ormo orno oro- orom oron oror orro orub orum oun- our- ourn ouro ouu- rbbb rbbr rmon rnbr rob- robb robo robu romb romm romo rono roob room roon roor roro roru roub roum roun rrrr rrum rrun rubb rubu rumb rumm rumo runn runo ruro ruru ruun ubbo ubon umb- umbo ummo umno umor unmr unno unon unro unum uomo uor- uro- urom uroo urum urun urur uuno uuuu