LAS VEGAS ? Col. Royal Mortenson, commanding officer of The Basic School, Quantico, Va., gives Marine officer selection officers a class about what is expected of officer candidates attending The Basic School. The Basic School is a follow-on course for Marine officers who graduate from Officer Candidate School. The course teaches Marine officers basic infantry skills. More than 100 Marines gathered for the fiscal year 2006 Officer Selection Officer Conference, held Dec. 12 ?15, in Las Vegas. - LAS VEGAS ? Col. Royal Mortenson, commanding officer of The Basic School, Quantico, Va., gives Marine officer selection officers a class about what is expected of officer candidates attending The Basic School. The Basic School is a follow-on course for Marine officers who graduate from Officer Candidate School. The course teaches Marine officers basic infantry skills. More than 100 Marines gathered for the fiscal year 2006 Officer Selection Officer Conference, held Dec. 12 ?15, in Las Vegas.