An F-111 was flying escort with a B-52 and generally making a nuisance of himself by flying rolls around the lumbering old bomber.The message for the B-52 crew was, "Anything you can do, I can do better."Not to be outdone, the bomber pilot announced that he would rise to the challenge.The B-52 continued its flight, straight and level, however.Perplexed, the fighter pilot asked, "So? What did you do?" "We just shut down two engines."