FALLUJAH, Iraq - Taking a short breather Friday, the 21-year-old Marine corporal explained what it was like to practice his lethal skill in the battle for this city. "It's a sniper's dream," he said. "You can go anywhere, and there are so many ways to fire at the enemy without him knowing where you are." The role of snipers has become a significant tactic for Marines in this "Sunni Triangle" city. Marine experts say Fallujah is among the most "target-rich" battlefields for snipers since the World War II battle for Stalingrad, during which German and Russian snipers dueled for months....