United States v. Arreola, 467 F.3d 1153 (9th Cir. Nov. 8, 2006) (18 U.S.C. 924(c)(1)(A), punishing "any person who, during and in relation to any ... drug trafficking crime ... uses or carries a firearm, or who, in furtherance of any such crime, possesses a firearm," describes two alternative means to commit a single offense).