knock against each other的用法和樣例：
例句
- Where there are two, it's the second that clangs against the first and makes noise.
戴雙鐲的手臂，鐲子互撞發出叮噹響聲。 - But during the collision, one galaxy can rip the other apart gravitationally, and dust and gas common to both galaxies does collide.
當星系互撞期間，星系可能因重力拉扯另外一個星系，塵埃與雲氣也會因此而合併。
