UNEXPONIBLE

be bi bo el en ex in li lo ne no nu oe oi on op ox pe pi un up xi xu

bee bel ben bin bio bop box bun eel eon inn ion lee lei leu lex lib lie lin lip lob lop lox lux neb nee nib nil nip nix nob nub nun obe obi oil ole one ope pee pen pie pin piu pix poi pol pox pub pul pun upo

been beep bene bile bine blin blip blue boil bole bone bunn ebon enol exon expo ibex ilex leno lien lieu line linn lino lion lipe lobe loin lone lope loup lube lune luxe neep nene neon nine nixe noel noil none nope noun open oxen peel peen pein pele peon pile pine pion pleb plex plie pole pone pule puli unbe upon