1. Whether the trial court committed plain error in refusing to grant a "buy-sell" defense jury instruction when the government's evidence of a conspiracy consisted of a series of buy-sell transactions.

2. Whether the trial court erred in refusing to grant the defendant's Rule 29 motion for judgment of acquittal when the government's evidence failed to prove the agreement necessary to establish the defendant's participation in a conspiracy.

Whether the trial court committed plain error in refusing to grant a 'buy-sell' defense jury instruction