firs[计] 先前的firn.枞树；冷杉；枞木firing duration燃烧持续时间firing strategy触发策略firn-jet head喷火头Firing sequence起爆顺序firing interval起爆间隔,射击间隔firging machine[机] 锻机Firing distance射击距离firing behavior烧成中性状态化firry woodlands枞树林地firing attitude点火姿态