阅读下面这首古诗，完成后面问题。
                                                                                                                 从军行 
                                                                                                                   李白
                                                                                        百战沙场碎铁衣，城南已合数重围。
                                                                                        突营射杀呼延将，独领残兵千骑归。
[注释]呼延：匈奴贵族，这里指敌军的一员悍将。