剑与远征雪与火最后一个宝箱怎么拿

击败怪物；开炮开炮；击杀怪物，打开宝箱；操纵机关；开炮开炮；击杀怪物，打开宝箱；击杀怪物，打开宝箱；操纵机关；操纵机关；开炮开炮；；击杀怪物，打开宝箱；操纵机关；操纵机关；操纵机关；开炮开炮；拾取宝箱；操纵机关；开炮开炮；操纵机关；操纵机关；开炮开炮；操纵