apply the good-cause exception to waiver because the defendant made no showing of cause in his opening brief and declined to make such a showing in a reply brief even though the government affirmatively argued that the defendant had waived his suppression arguments). Accordingly, we affirm the district court’s order denying McCoy’s motion to suppress. II. Final Judgment McCoy next argues that the district court’s final judgment of conviction was tainted by an erroneous jury instruction. Specifically, McCoy argues that reversal is warranted because Instruction 26 — the aiding-and-abetting instruction — contained language similar to the aiding-and-abetting instruction that the Supreme Court rejected in Rosemond v. United States, — U.S. -, 134 S.Ct. 1240, 1251-52, 188 L.Ed.2d 248 (2014) (<HOLDING>). Where, as here, a challenged jury instruction
holding that government proves aiding and abetting of  924c crime when it proves that defendant 1 actively assisted underlying offense or use carry or possession of firearm 2 with advance knowledge of that firearmrelated conduct holding that the district courts aidingandabetting instruction for 18 usc  924c prohibiting the use or carry of a firearm during any crime of violence or drug trafficking crime was flawed because it failed to explain that the defendant needed advance knowledge of a firearms presence holding that to enhance a sentence because of the defendants use of a firearm the jury must find the defendant guilty of a crime involving a firearm or otherwise specifically find that a firearm was used holding that to be guilty of aiding and abetting under  924c the defendant must have directly facilitated or encouraged use of the firearm mere presence at the scene of the crime and knowledge that the crime is being committed is not enough holding that a court must only look to the statutory definition not the underlying circumstances of the crime to determine whether a given offense is by its nature a crime of violence for purposes of 18 usc  16