During a simulated attack, the troops have to defe...

During a simulated attack, the troops have to defend themselves against an imaginary enemy, as the sergeant calls it. Bawling out orders, he notices that one recruit shows little response. "You there, the sergeant shouts, "the imaginary enemy is advancing, and your are caught in the crossfire. Action! The recruit takes two steps to one side.
"What are you doing, man? Yells the sergeant, purple with fury. "I`m taking shelter behind an imaginary tree, Sergeant, answers the recruit calmly.