is the only sign is the only solution is the only source is the only spanish is the only species is the only sport is the only state is the only sure is the only surviving is the only survivor is the only team is the only temple is the only thing is the only thing i is the only thing keeping is the only thing left is the only thing they is the only thing we is the only time is the only time i is the only time we is the only time you is the only tool is the only town is the only treatment is the only true is the only truly is the only truth is the only viable is the only way is the only way forward is the only way i is the only way out is the only way you is the only weapon is the only woman is the only woman i is the only world is the onset is the ontario is the open is the open source is the opening is the opera is the operating is the operating system is the operation is the operational is the operations is the operative is the operative word is the operator is the opinion is the opium is the opponent is the opportunity is the opportunity cost is the opposite is the opposition is the optical is the optimal is the optimal solution is the optimization is the optimum is the option is the optional is the oracle is the orange is the orchestra is the order is the ordinary is the organ is the organic is the organisation is the organization is the organizational is the organizer is the orientation is the origin is the original is the original one is the original version is the originator is the orphan is the other is the other guy is the other half is the other key is the other main is the other major is the other name is the other one is the other part is the other person is the other reason is the other side is the other thing is the other way is the other way round