MARINE CORPS AIR GROUND COMBAT CENTER TWENTYNINE PALMS, Calif. - A U.S. Marine M1 Abrams tank attached to 1st Battalion 6th Marines defends its position for the Clear Hold Build 3 exercise with Regimental Combat Team 5 during Enhanced Mojave Viper here June 15. As the first regimental combat team to participate in EMV, RCT-5 will fine tune its command and control capabilities during this combined arms exercise.