Tracy Yu, student, University of Southern California, fires at simulated enemies at the Battle Simulation Center during a tour of the Combat Center, March 4, 2014. The majority of the tour participants expressed an interest in working with military families upon completion of their schooling. (Official Marine Corps Photo By Lance Cpl. Kasey Peacock/Released) - Tracy Yu, student, University of Southern California, fires at simulated enemies at the Battle Simulation Center during a tour of the Combat Center, March 4, 2014. The majority of the tour participants expressed an interest in working with military families upon completion of their schooling. (Official Marine Corps Photo By Lance Cpl. Kasey Peacock/Released)