without provocation

基本解释

The unarmed man was allegedly pulled from his home and shot to death without provocation.
据称，这名徒手的平民被从家中拽出，无缘无故即被枪杀。
They sting or bite without provocation; they fly uninvited into our rooms on summer nights, or beat ageist our lighted windows.
它们无缘无故地又叮又咬；夏天的晚上，它们未经邀请便飞到我们房间里，或者对着露出亮光的窗户乱扑乱撞。
Among subjects who hadn't eaten the raisin, those who were told they'd been rejected by the group became aggressive, inflicting long and painful sonic blasts without provocation.
在没有吃葡萄干的研究对象里，那些被告知被团体拒绝了的人在没有受到刺激的情况下变得好斗，造成持续时间长而痛苦的快速爆发。

In 1976, North Korean soldiers viciously murdered American servicemen with axes without provocation.
CENTERFORSECURITYPOLICY: Center for Security Policy Must History Repeat Itself? Congress Should Not Invite North Korean Aggression